This was an PBP arena game, so all the characters were pretty munched. At level 10, my Barbed Devil could reliably deal 50 damage a round due to exploiting Produce Flame, Beast Claws and a Ring of Shocking Blows. But that paled before the awesome brokenness that was some of the other characters.
One was the griffon-riding paladin saint (exploiting the grossly inadequate +2 LA) who would do flying charges to deal 100+ damage.
Or the ghaele eladrin. He would use Ethereal Jaunt to hide (thankfully, 3.0 revised that spell to level 7) and would hide in an object, buff up with every cleric spell ever published anywhere, then emerge from the Ethereal and kill you. Unless you also had Ethereal Jaunt, fights would be very boring.
Or the druid / shifter with Energy Drain armour that also had the Wild quality. He'd change into something with silly strength (Feral Annis Hag, Insectile Troll) and touch you to death.
The worst one was the anthromorphic baleen whale cleric with an intelligent sword. Due to the wonkiness of 3.0 Haste, he had three spells per turn, one from his sword. AC in the middle 40's, easily with no sacrifice in combat effectiveness, along with blindsight and absurd natural armour. Anthromorphic whales were very popular in that place, exploiting the fact that you only needed to sacrifice 3 levels and didn't get any LA in return for incredible stat boosts, 12 or so natural armour and blindsight.
Arena games really expose you to the true horrors of brokenness, when roleplaying is an optional extra. Fortunately, the epic level arena I'm in at the moment (
gratuitous link--I play Kiri and Mazikeen) is much better about broken material, nerfing anything that seems too unbalancing--such as the recent guy who used Fission, Schism and Font of Power to spit out 4 Huge astral constructs per round at no PP cost.