The Gladiator Arena

Its meh again. And I would like to give some feedback about the arena. So to start off lets talk about the boss rotation. Ive found that every time I enter the arena, I get all the bosses that dont grant achievements. I have only run into two achievement bosses and one of the is ridiculously OP. Bloodhammer+ the flag bombs= death.
Its extremely hard to survive in the first place, but the vortex bombs? Its nearly impossible to survive a hit from one flag bomb, but if you do survive a second bomb drags you in. I feel that the flag bombs are way too powerful. And also, Has anyone encountered this "Challenger" Yet? We have done ten full runs and not encountered this guy yet? Any responses or thoughts are helpful.

I'm also wondering what the challenger is...

yea please tell us who is this challenger i ran this map like 40 times feels like and nothing

Exactly, who the heck is he?

Isn't the challenger the guy from undead the Captain?

rogue and mage very hard to survive in arena..and cost much of platinum to win this gladiator arena :(