This mod adds an enchantment that when hits an entity applies an effect that works kinda like poison, dealing damage every 3 seconds but when it expires it deals damage depending on how much damage was inflicted (ignores armor for now) and the max health of the target and the level of the enchantment.
Almost everything is configurable, so if u don't like anyhting of theese the options (like the posion-like damage part) you can disable them.
(the enchantment is registred as a curse but it does not have downsides yet).
Feel free to use this mod in your modpack!