If it wouldn’t make the in-game explanation very extense, and convulated, a mix of 10% damage based on current life total but with a minimum damage based on the rarity would keep it at an acceptable risky level to me at least.
Maybe we aren’t taking the whole problem as we should, because one factor that increases the trouble is how easy it is to gain life with spells, something that also makes the life gain traits look so pale… I think the creation of a new effect is due:
Corrupted: Prevents healing, life gain and natural cleansing of negative effects on the aflicted troop.
This is something that i would like to see added on Plague’s spell, not that i don’t like the part of decreasing skills, but disease just doesn’t feels enough as a mythic effect…