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.
In 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.