A fatigue mechanic makes sense, but I think it ramps up too fast. If it kicks in as 2x at round 12 (or whatever it's set to now), it should maybe double every 5 rounds afterwards, or increase by 1x every round, but doubling so quickly means the fight just instantly ends as soon as it kicks in. Apolonia's DPS is so lacking that I found myself having to dump 100% of my points into attack when I was first reaching the level 2000-3000 range in order to kill anything.