Doom is a debuff effect that places a counter onto a target. The counter decrements by 1 at the end of the target's turn. Once the counter reaches 0 and the target’s turn ends, the target dies, regardless if the target has KO Resistance effects active. Upon death, the target cannot be revived for a certain number of turns, even if the unit does not die as a result of Doom.
If Doom is reapplied to a unit that already has a Doom counter, the unit's Doom counter will refresh to the most recent Doom debuff applied to it.
Doom with a counter of 0 will not take effect on units if all enemies are defeated by the end of the player's turn.
Doom cannot be cleansed by any means with the exception of units such as Cosmic Shade Kranus and Sero-Anya, Eternal Light who can cleanse Doom using BB or UBB provided either one of them has the SP Enhancement option unlocked and through the Elemental Synergy Pyre.
Elemental Synergy: Pyre
Elemental Synergy: Blast
Upon using a Dual Brave Burst with the Blast synergy, the squad will be invulnerable to Doom and when the Doom counter reaches 0, the units will not die at the end of the turn as a result of Doom.
Elemental Synergy: Prism
Upon using a Dual Brave Burst with the Prism synergy, the caster will KO itself. Additionally, the unit cannot be revived until the current wave has been cleared due to Doom being applied.