Adds a layer of Plague to all enemies and summons a Doom Carrier to attack an enemy target. Plague effect can stack, and at a certain number of layers, it will convert into a Doom Curse. A Doom Curse continually drains HP based on a percentage of total dmg dealt by Plague effect. If the target dies, a Doom Carrier will be summoned over the dead unit to fight for the allies (Doom Carriers inherit a certain amount of Doomia's overall attributes)