Horizon of Darkness

I just realized that there's a more likely way the curse works: it prevents health regeneration, like in some games. It would be an effective combination with bleeding, for example.

Another observation: they are clearly using level 6 skills against us. However, I expected this at least from the mage, so it's nothing.

Joe: move 1 unit northeast (or however needed so that Ara can hide under the Veil?), use Harpoon Cannon V on the mage.
Zeikin: use Overcome IV, move 1 unit northeast, move 3 units north (so that he can also hide under the Veil).
Radiel: if he can transform into a dragon from his current position, he does so. If not, he moves above Arael and does it there.
Henry: on the first turn, stuns the swordsman with Spirit Drain V (I assume the spirit is present and visible). On the second turn, I want to check the mage's HP.

Joe takes 150 damage (1355 | 1822)
The mage restores 150 health (3051 | 5445)
Joe moves 1 unit and uses Harpoon Cannon V
The mage takes 1302 damage
The mage (1749 | 5445)
Zeikin moves 4 units and uses Overcome IV
Bleeding is stopped
Radiel transforms into Nightmare Avatar (3633 | 4083)
Henry moves 11 units and uses Spirit Drain V
Swordsman is paralyzed for 1 turn