The Undead Mage has had an ability called Blightstrike since very close to the beginning of the game. The idea was that it was a single point cast that would poison enemies. The first time I wrote the ability it was an AOE splash that was position based. Then I changed my mind, and made it single targeted, but still poisoning with damage over time.
What I found was that the ability was either too effective or not effective enough. Casting frequently for the undead feels weird, and poisoning an entire army in 3-4 casts also felt weird because of the amount of visual debuffs.
Now Blightstrike has been reworked into Deathcoil. Whenever a nearby undead unit dies, the mage has a chance of releasing a blue projectile (see gif), that flies out to strike at an enemy near where that unit died. This ability is passive.
n the first gif, you can see that the RNG was lucky and we had a tripple-proc releasing three projectiles at the moment of one unit’s death. Lets see how this ability holds up in the next round of playtesting.