Cygnus vs. Akyrum Expedition

And that's why they allow you to respawn in the same map

(I've lost 15% on one Akyrum run before )

Exactly the problem. So if you're fighting the regular Akyrum, you better have 0% or you're going to lose all of your level's progress. That could be days of training/bossing if it's not on GMS. That's idiotic. No boss should be built around the aspect of players dying for half the fight.