We know xp necessary increases per level up.
When he was level 26 he got 1558 xp and leveled up to 33 that's 7 times. Even if we're generous and split it even that approx 222 per level up...that doesn't make sense when before that he got 150 xp for a gargoyle and said it wouldn't be enough if he kept hunting there... Cause even then it'd just take 2 gargoyles....they really flubbing the math
But he might be a summon so I'm still holding off. He reminds me of that guy that worships Thanatos in that other comic. WHOOOO and smashes his head against stuff? Idr the name.