Jack99
Adventurer
Let me see if my math is right.
Average AC for a fighter at level 20 is about 33 (did a quickplay character in the builder).
Fighter Turn 1: "I mark you, you big stinky-headed nasty thing"
Hydra Turn 1: "Oh yeah, I eat heroes. 5x +27 vs AC; 1d10+12 a hit - if two hit, take an extra 10." "Oh yeah, and action point."
150 average damage against the marked guy.
I think I'm in love.
Sounds like your problems with challenging your players are going to be solved, huh?