Thanks a lot for the quick answer (especially considering how salty was my mrssage, sorry about that by the way)
Unfortunately, I don't have any record and I don't remember how it proc it himself but the fact is in this specific battle the thing escalate too fast, the boss damaging himself (and I almost won it, the bast4rd was 3hp left).
The infuriating part was the fact that I didn't even take a scratch against the first boss and came here with full HP, only 2 wounded followers and a bunch of blessed ones :/
I played a game today and I beat it again (at least he surrender, but I'm pretty sure I would have beat it anyway).
I'll try to fraps my next games and send it to you if it do it again, I really don't understand what happened during the last game.
When it doesn't proc it by himself, it's skill is ok (but it can screw you nontheless, depends on your draw, I still think there is a real difference between the final boss and the rest of the game (except a bunch of decks which are really annoying too but they can be tied to special events). However, maybe it can be hard as it is, considering the fact that you don't even need to start the fight against him to win the game)
I'll try to catch you on discord :)
And I want to stress and say it one more time: your game is amazing and is totally my new FTL.
(A side question: what do you plan to do for the release: a wipe of the saved profile or will we keep our current progress ?)