|There's gonna be cursing|
|Self Ability|| Discharge
Enemy Ability: Doom
This ability deals no damage, but places the Doom Hex debuff on the target. This debuff has a duration of 2 turns, and deals 60 damage to the target when it runs out. If the hex is removed before it runs out normally, it does not deal damage.
Self Ability: Discharge
This ability damages all heroes for every buff or debuff that's placed on them.
You need to be quick about killing the Djinn. Focus on dealing as much damage as possible before the Doom debuff starts killing your team. It deals exactly 65 damage, regardless of Armor, so usually you can take a single hit (or two, with some healing) without consequences.
Having some heroes can also make the fight much easier. Knight can Protect another character and Purge the debuff, buying you another turn. Monk can remove it with Heal if it only has 1 duration left, and the Diverter can just Convert it.
Using a buff item, such as Troll Heart, Victory Horn or Aegis, may make the Djinn more likely to cast Discharge instead of Doom, which will spread the damage across your party. Though less effective, Witch and Diverter are also able to buff the entire party at once.