The game has a bug.
I got up to the Proteus battle, killed him, clicked the check mark to gain a level....... and all of a sudden I get a screen saying that Proteus killed Gladiater. What makes this darkly humerous is that I can still see the screen in the background saying Gladiator killed Proteus. If you would like I can send you the screen capture to verify this/ help you debug it a little bit. However, for fear of this happening again, I'm done with this game. On the bright side, it was fun while it lasted.