But the idea isn't to make an RoE Spender build - the idea is to get the strongest possible Locust Swarm to melt trash (chaining Haunts also works well with this so RoE is good) but then also having something to take out elites. You don't spam Haunt on elites (because there is no way to get Jade 2p sadly) so you are free to cast another spell at that point - and the good thing about spiders is that you get a bigass controllable spider pet that also benefits from all your spider buffing that is always doing damage.
Obviously it's still unlikely to be a great build because Arachyr sucks, but I like its base concepts of a strong Locust Swarm (Jade also uses swarm but its a weak swarm used in a different way) and a controllable pet. If nothing else at least it might give the set a bit of feeling of identity.
A RoE arachyr build might work as an elite targeting build -> Angry chicken to elite, piranado, haunt spam then firebats.
A separate thought is that when Focus and Restraint was introduced it was awkward to add a primary skill into the rotation to get a 2.25 multiplier. Now we're looking at adding a haunt into the rotation to get a x4 multiplier against those haunted targets.
Things that work with ROE are: Jade, because it naturally always used Haunt. And HT, because you don't really need to cast third mana spender as GARGS do all damage now, Zuni = same. But ROE is nerfed for pets, so we remove Zuni and HT. Only Jade stays.
You forgot about LoN. A LoN RoE spender build just might work:
Haunt + Locusts + Toxic Gem each doing x56 damage [ x14 from LoN and x4 (RoE)].
Having an additional skill to spam once everything is haunted might be useful (even if your just using it for elites and rift guardians).
A separate thought is that when Focus and Restraint was introduced it was awkward to add a primary skill into the rotation to get a 2.25 multiplier. Now we're looking at adding a haunt into the rotation to get a x4 multiplier against those haunted targets.
You forgot about LoN. A LoN RoE spender build just might work:
Haunt + Locusts + Toxic Gem each doing x56 damage [ x14 from LoN and x4 (RoE)].
Having an additional skill to spam once everything is haunted might be useful (even if your just using it for elites and rift guardians).
If doing a locust focused build, you are better off dropping spiders and putting in haunt and wearing RoE.
This gives you a 4x damage multipler on targets that have both haunt and locust.