Urogrim is one of the best epics in the game. With really good gear, he can farm Dragon 25 solo, so you could run 4 uncommens to get XP while doing dungeons.
If you don't have the gear required for this yet, Urogrim is still a fantastic champ in high level dungeons. The combination of poison and healing he brings is great, and with a 20% spd aura in all battles he is a good teamleader. I use him in my teams for Dragon, Ice Golem and CB.