http://us.battle.net/d3/en/forum/topic/14730473069 (this is my old one but it didn't get many replies, so pls, comment the one up here
Battle.net EU Forum Thread: http://eu.battle.net/d3/en/forum/topic/12286639114
Reddit: http://www.reddit.com/r/Diablo/comments/2i8fev/suggestions_battlegrounds_of_eternity_black_realm/
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Hi guys!
I'm back again to suggest a couple of ideas I had in mind, for additional Challenge Mode "PvEvP-games".
First off I want to say that my fist idea (Battlegrounds of Eternity) was inspired by my friend Uranux's idea (you can check it here).
Unfortunately he didn't get replies on his thread but please, if you have some spare time just give it a read because, trust me, his idea is really valid!
With that said let's start!
TLDR version at the end of the post!
Battlegrounds of Eternity
I thought it would be really really nice to revisit old places, redo old quests and kill again old bosses.
But how to make it happen without ruining the lore?
In the battlefields of eternity, in act 5, you can find "time prisons" where battles of the past got time-stopped.
When you "pop" the "time bubble", the monsters will "awake" and attack you.
I thought that in the mess that it is the Pandemonium Fortress (and its surroundings), there might also be "time-bubbles" that bring you back in time.
I don't know if it could fit the lore, but anyway I think that the Battlegrounds of Eternity could be a nice addition to the game.
So, what are BoE?
The Battlegrounds of Eternity are maps where you have to complete quests in order to progress and then kill the final boss.
Pretty easy, but the nice things are that you will redo old quests, kill old enemies (such as Baal, Mephisto etc.) and that you will compete against other players.
Let's start with some images so you'll have a better idea of my suggestion:
As you can see, you can choose which battleground to play, and each one will have different quests and monsters/bosses to kill.
You can also choose how many players you'd like to fight against
But first let's have a look at the "details and options" pane.
Time-defeat disabled
This refers to the "Race against time" option which I will talk about later.
Rewards based on quests completed and progress-difference between teams
This means that the more quests you complete (in a battleground there are bonus quests that you can skip) and the more difference there is between your team progress and the enemy team progress, the more rewards will get the winner team.
"Which rewards?" you might ask... well I don't know. Depends what Blizzard has in mind with PvP/PvEvP (if they'll ever implement it): they could be "PvP points" for ladder ranking or a "PvP currency" that allows you to buy PvP cosmetic rewards, sigils, banners etc.
Let's now jump inside a game:
Who of you does remember Dac Farren? 
As you can see the maps between the two teams are exactely the same (this is also true for monsters, placement of the monsters and everything else) and you can always check your progression and your enemies' progression as well as their position on the map.
To progress you have to complete quests (bonus quests are there for more final rewards) and when you have completed them all on a "floor" you can continue to the next "floor".
When you are at the final "floor" and you completed the final quests, the boss will spawn.
The first team to kill the boss will win.
In the case of The Siege of Harrogath you will have 3 total floors to complete and then you'll have to kill Shenk the Overseer to win.
A note about BoE is that you cannot resurrect.
Once you're dead, you're dead for the rest of the battle:
there will be a "ghost mode" so you can follow and see what your allies are doing and in case all your team is dead you'll have the opportunity to watch the enemies.
Yes, there might be no winners in case the members of both teams die.
Let's take a step back and explain what "Race Against Time" (RAT) is.
Now "Time defeat" is enabled.
Basically when you enable RAT you will also fight against time.
This means that both teams have a set amount of time to finish the battleground.
If they can't make it they will both lose.
Of course, as you can see from the image, the rewards will be higher depending on the remaining time.
Here you can see the RAT version of a battleground:
If this idea will ever get implemented, it would be nice to have many battlegrounds to play.
At first there might be only few of them but as time pass the devs could implement more of them:
There might be the Chaos Sanctuary where you have to open the five sigils to free (and kill) Diablo and where you have to kill the Sigil guardians such as Lord De Seis (and these guardians could be Avatar monsters. If you're wondering what an Avatar monster is just check Uranux's idea here), there might be the Old Tristram "event" where you have to help Lachdanan kill his king, there might be the Tal Rasha Tomb where you have to free Tyrael and kill Duriel etc.
Black Realm
Did you wonder where the fragments of the Black Soulstone have gone?
They're spread all over Sanctuary and while many evil souls have been released, some of them are still inside these fragments and are trying to get free.
This influences the Nephalems' sleep making their dreams become nightmares.
While in these nightmares the physical body of the Nephalems will remain safe but their minds might become corrupted.
In order to maintain sanity and to purify the fragment, the Nephalems must destroy the "Nightmare Summoning Portals" and at last the Black Realm boss.
Unfortunately many Nephalems are "connected" to these fragments and only the fastest one (team) have the possibility to escape the nightmare.
How it works
Both teams will play on a random generated map with exactely the same shape, placement of the monsters, monsters type, etc.Every map has 4 portals and each of them spawn on a different lane (more on this later) and they'll keep summoning monsters on a regular basis.
These monsters will always follow the players, no matter how far they are.
A Summoning Portal
Every summoning lasts for 3 minutes (I'm calling these summonings "rounds") and then a new one will begin with new type of monsters, and all the "old" monsters will perish.
Kinda what happens on the Realm of Trials where you get the Greater Rift Keys.
What's the difference between an "endless wave dungeon" and this idea then?
There are many differences and I'll try to be as clear as possible (images will help me achive this I hope).
The main difference is that a certain amount of monsters killed by one team in next previous round will spawn at the start of the next round on the other team's map at the nearest Summoning Portal.
These monsters will also have a 50% damage, health and movement speed increase boost and they will NOT count as kills.
This means that the teams will not fight only to be the first to destroy the summoning portals but also to kill as fast as they can and as many minions as they can so they can slow the other team's progression.
Now I won't list all the differences one by one, however I will keep explaining and you'll see all other differences on your own.
Summoning Potential
As I wrote above, a certain amount of monsters will spawn on the other team's side at the start of a new round.This amount is determined by the "Summoning Potential"
Every Summoning Portal still active gives the team a 10% summoning potential.
At the start of the game, each team will have a base 40% summoning potential.
So, if at the end of a round, both teams didn't destroyed any portal, at the start of the next round each team will see spawn 40% of the enemy team's total kills obtained on the previous round.
E.g.
If no portals are destroyed and the blue team killed 100 monsters and the red team killed 80 on round 1, at the start of the round 2 the nearest (to the players) summoning portal will spawn 32 "red minions" for the blue team and 40 "blue minions" for the red team.
This "summoning potential" is diminished by 10% for each portal destroyed but if one team has more portal destroyed than the other one, then the team who has the less amount of portal destroyed will receive a "summoning potential penalty" that increases the base "summoning potential" by 10% multiplied by the difference between the two team's portals that are still active.
E.g.
If the red team is the first to destroy a portal (so it's 1-0 in favor of the red team), then the red team summoning potential will be 30%, while the blue team will receive a penalty of 10% and will see its portals reach a 50% summoning potential.
If the score changes to 2-0 for the red team, the red team will have a summoning potential of 20% while the blue team will have a it at 60%.
If the score changes again to 2-1 for the red team, the red team will always have a summoning potential of 20% while the blue team will see its own go down to 40% (10% for each summoning portal still active and 10% for "score difference").
One last example, if the score changes once again to 2-2, then the summoning potential for both teams will be set at 20%.
Portals Guardians
Each lane (more on this later) will have 3 Portal Guardians that make the Summoning Portal invulnerable until they are dead.This Guardians are very strong unique monsters and will slow a team's progression also because they don't count as kills.
Team Minions
Team Minions are the monsters that are summoned for the enemy team at the start of a new round and that will help your team to slow the enemy one.As I wrote earlier, these minions have their damage, health and movement speed increased by 50% and they do NOT count as kills.
A Blue Minion has spawned to fight the Red Team
Elites
Every now and then, the nearest Summoning Portal will spawn a pack of Elite Champions (blue elite).These packs do not count as kills but they will increase the potency of your team's minions.
This means that for every pack of elite killed, the Team Minions receive a 2% damage, health and movement speed increase boost!
This potency is reset whenever a new round starts.
Note: remember that all numbers you see here are just examples!!
Normal Black Realm
Now that the majority of my idea has been explained I can continue with other details.
As you can see there are more elements I have to explain, but once again let's slow down and explain everything in detail.
Straightforward-style maps
This means that the random generated maps are "mirrored maps" and every element on the map is placed in a "linear" manner.
Portal Guardians have no minions
This is self-explanatory
Portal Guardians deaths do not increase monsters summonning rate
Differently from Chaotic Black Realm, everytime you kill a Portal Guardian it doesn't increase the spawning rate of monsters from Summoning Portals.
For example in a Chaotic Black Realm if a pack of monsters spawns every 10 seconds, when you kill a Guardian, this spawning rate will increase and the pack will be summoned every 9 seconds.
Note: remember once again that numers are just an example
An example of a Normal Black Realm map
Note 1: remember that maps are not explored at the start of a game!
Note 2: while some icons might be easy to recognize, some of them might be "confusing".
Don't worry because I will explain them later.
Don't worry because I will explain them later.
As you can see from the image, you can notice that there are 4 "lanes" and each lane has 3 Portal Guardians and a Summoning Portal.
To destroy the Summoning Portal of a certain lane you have to kill all three Portal Guardians of that same lane:
The last Portal Guardian of a lane has been defeated and now the Red Team can strike the Summoning Portal
Once a team has destroyed all 4 Summoning Portals, the Black Realm Boss will spawn it must be killed in order to achieve victory:
The Blue Team is a bit slow and the Red Team has already summoned the Black Realm Boss!
Adding complexity: Nightmare Pillars
What are these "Nightmare Pillars"?
These are destructible "objects" that weaken the players.
If Nightmare Pillars are enabled they will spawn (3 of each) in the Black Realm.
There are two types of Nightmare Pillars: Disrupting and Constraining.
A Disrupting Pillar
The first type will slow players' movement speed (this includes "animation speed" for "travelling abilities" such as leap, vault etc.) while the second one will decrease the amount of damage the players do.
Each Pillar have a malus of 15% which means that players will start with -45% movement speed and damage.
This is the debuff of 3 Disrupting Pillars
This is the debuff of 3 Constraining Pillars
These Pillars work in a similar way of the one of Summoning Portals:
the team who has more destroyed pillars will give the other team a penalty.
E.g.
If the red team has 1 Constraining Pillar destroyed while the blue team has 0, then the red team will have a 30% damage penalty while the blue team will have a 60% damage penalty.
This means that if a team is winning with the score of 3-0 Constraining Pillars destroyed, that team will have 0% damage penalty while the other will have a 90% damage penalty!!!
Note: here again.. numbers are just examples!
With Pillars enabled you will have much more tactical games and they add a bit of RNG because you don't know where they spawn (even if in Normal Black Realm it's easier to find them) so the first team that find them might get a bit of advantage but since this is an option, why not?
Pillars won't be easy to destroy, as at 50% health they become invulnerable and spawn a "Pillar Guardian" that is a unique monster with great powers and that does NOT count as a kill.
Once this Guardian is killed the Pillar will become vulnerable once again and you can destroy it.
Teams: 1vs1, 2vs2, 3vs3, 4vs4
Of course there is the option to choose with and against how many players you can fight:
Adding even more complexity: Chaotic Black Realm
The main difference between a Normal and a Chaotic Black Realm is that the maps in the Chaotic one are not "mirrored" and all "elements" are placed at random.
An example of a Chaotic Black Realm map with Nightmare Pillars enabled
An example of a Chaotic Black Realm map with Nightmare Pillars disabled
Portal Guardians will also have minions (they are not needed to be killed in order to make a Summoning Portal vulnerable.. but they hurt!).
In addition, everytime you kill a Portal Guardian, the summoning rate of monsters will increase:
Entrance Portal
Whenever you destroy a Summoning Portal, an Entrance Portal will activate and they can be used to return at the start of the map so you can reach faster the next Summoning Portal:
Remember that summoned monsters will always follow you, so beware to use an Entrance Portal at a middle of a round because when you will teleport at the entrance you might retrieve you to be inside a mess
Another example of a Chaotic Black Realm map
As you saw, I showed you an example of a Chaotic Black Realm map but you might have been confused because the map was not very "messy", so I will show you another example of a Chaotic Black Realm Map:
With this you might get even more confused, but I can assure you that every element is where it must be and to prove this here's an easier image to understand:
This is the map version for the Red Team. You can tell this by looking at the color of the icon of the "Black Realm Entrance"
Teams Details
The last thing I want to show you is the "Team Details" pane:
Notice that the Summoning Portal penalty is refered to the malus you get to Summoning Potential whenever your team has less Summoning Portals destroyed than the other team
And to have a better idea of how "everything" works here's a .gif image:
I hope numbers are correct lol 
Player Deaths
As for BoE, also in Black Realm whenever a player dies, he cannot resurrect.
About Hardcore characters I think that it would be nice to make the death not permantent (for both BoE and Black Realm) so they can enjoy as much as they like these two challenge modes but this would go against the "hardcore phylosophy" so I thought that an alternative is to allow only the Normal Black Realm to not have a permanent death while the other two modes (BoE and Chaotic Black Realm) will make them RIP forever.
Remember that even if a team loses its members won't die of course.
Conclusion
Alright guys!
I've finished.
I hope you enjoyed it as mush as I did to create all of this!
P.S. If you're wondering what Wave of Death, Defence of the Outpost and Infernal Rift are and how you can open "the challenge mode window" have a look here
P.P.S. Sorry for my not-so-perfect english :/
If you have any criticism or would like to write a comment please don't refrain from posting!
TLDR Version
The Battlegrounds of Eternity are maps where you have to complete quests in order to progress and then kill the final boss.
Pretty easy, but the nice things are that you will redo old quests, kill old enemies (such as Baal, Mephisto etc.) and that you will compete against other players.
Black Realm
Both teams will play on a random generated map with exactely the same shape, placement of the monsters, monsters type, etc.
Every map has 4 portals and each of them spawn on a different lane (4 lanes total) and they'll keep summoning monsters on a regular basis.
A certain ammount of these summoned monsters will spawn in the other team's summoning portals at the start of each round so they'll slow the enemy team's progression.
A team must destroy these Summoning Portals before the other team does and in order to make them vulnerable to attacks, players have to first kill the Portal Guardians.
There are options to make these maps more tactical and to add some RNG such as enabling "Nightmare Pillars" that weaken the players' powers or by choosing a Chaotic Black Realm that will generate "non-mirrored" maps.
1
I've been trying all kinds of different builds and skills with my witch doc, and although it isn't the most efficient its a hellova lot of fun. I just reset my quests and am playing the game straight through. Sure the story isn't the best but for me it's more fun running all different acts and quests, and killing all the different types of monsters.
But then again players can have fun doing chest runs, or the Mira run, or whatever over and over. To each his own, just my opinion.