Tal rasha will let you use whatever skill you want, the key is to use 4 different element to maximize the damage. But which skills you use is completly up to the player. Of course there is stronger build (meteor being the primary skill you should use). But I think Tal rasha can be very good with many other skills.
And there will be a new set based on slow time and twister/arcane orb. So you might be on the look for this new set in 2.2.
Delsere's Magnum Opus
(2) Set Bonus
Casting Arcane Orb, Energy Twister, Magic Missile or Shock Pulse reduces the cooldown of your Slow Time by 2 seconds
(4) Set Bonus
Enemies affected by your Slow Time take 2000% weapon damage every second
This damage type will be determined by your highest equipped +% Elemental Damage
(6) Set Bonus
Enemies affected by your Slow Time take 750% more damage from your Arcane Orb, Energy Twister, Magic Missile and Shock Pulse
That is the set as of right now. It might change but its unlikely.
Enjoy Cuz i will. No more running around and dealing only DOT damage
Also triumvirate is getting updated, instead of the 10% ele damage for 3 elements, it's arcane orb deals 80-100% more damage after casting sig spell and stacks 3 times for up to 300%. Buff lasts for 6 seconds. This works nicely with the new set and I was seeing 500mil crits with frozen orb on PTR.
WIth Delsere's set, frozen orb easily hits the 1b marker.
I can confirm that. I put in about 30 hours on the PTR. I didn't have the Iceblink gem (I didn't bother with seasonal on PTR) so I didn't spend long on a DMO Ice build. That being said, i was hitting about 1.8B crits with Frozen Orb when i did a few GR runs under an ice build.
Delseres, plus triumvirate, plus Bastions of Will. Those all seem to synergize well. What's the preference for the weapon slot?
Gesture of Orpheus. 35% CD reduction on Slow Time. It's really nice for "Oh Shizzle" moments because you basically have Slow Time ready all the time. That being said, that weapon isn't strictly necessary to make the build work if you are careful. Anything that boosts your elemental damage of choice, or something with a desirable effect would work.