Tlessa has a concept that becomes more apparent later, it’s called Voidance and Devoidance. In game we call this Devouring Light (Voidance) and Devouring Darkness (Devoidance).
Enemies in special locations, starting on surface, have small amount of these stats. The further down the plane list you go, into Purgatory, the higher these values on enemies become.
There are various quests to do which grant items that increase both stats.
Holy Items also increases these stats later when you have access to the Purgatory Smiths Work Bench.
These will fire automatically, after you click attack and before you click the attack button. This is what’s called pre battle effect’s
How do this work?
Once you start getting further along in the game, you will run into creatures that void you. This means your fancy equipment that boosts all your stats, becomes useless. None of your enchantments will fire, you will use base stats for everything.
Note: If you are voided, your rings and affixes will not fire. However, your secondary ring effects will still fire on the enemies turn. This includes spell evasion and healing reduction (to the enemy)
This can be mitigated by you having Devouring Darkness (Devoidance) which will stop the enemy from being able to void you.
Some enemies also have Devouring Darkness which prevents you from voiding them. This is where resistance enchantments come in.
Voidance and Devoidance last the entire battle.
What about PVP?
In pvp, resistance enchantments are also needed to reduce the other players Devouring Light and Darkness Resistance.
Monsters and celestials do not have resistances to devouring light or darkness, but players do. If you can reduce their voidance/Devoidance, you can have a chance to ne shot kill them.