Nullzone
Explorer
Rapid Combat Challenge. Look it up.
Granted, after playing 2 adventures with this set up, I have had it come up all of zero times. Either monsters obey the mark, throw out rather annoying multi-target attack, or they toss me halfway across the battlefield and dominate me.
Although, considering the DM either respects the mark, or uses tactics to try and avoid it, I guess that means I'm doing something right.
Ah, silly me, I never think to look at epic.
Still though, how are you triggering Combat Challenge and Divine Challenge at the same time? You can't usually mark with both.