Hey! So I was toying with Diviner set which adds a projectile to Devastation, and then high cooldown reduction to be able to get two casts of Devastation at once, effectively quadrupelling the original damage -
https://www.grimtools.com/calc/w26ooJ8V
This is just a meme/draft idea, so the build is unfinished, but so far it looks like it’ll deal fantastic damage. 
Happy theorycrafting!
Unfortunately the devastation skill description says “Only one Devastation can be cast at any one time.”, or is there some item that eliminates this restriction (like spellscourge eliminates the off-hand caster requirement)?
Oh nooooo~ My dreams, shattered…
I wonder if this was patched in recently or something. I swear I remember having a few Acid Devastations going at once on a previous meme build…
Anasteria’s legendary helmet has another Devastation proc. I think that’s the only way to have two Devastations at once.
It has been like this since as far as I can remember. That you can only have one active devestation at the time
arcanist + outcast helm + apocalypse
tho you wont get modifiers for the last 2 since they are item granted skills