This is my top priority for Skyrim modding. I'll make an arena mod with 5 different arenas (I'll copy some "already in good shape for an arena" sections, like the Temple of Kynareth in Whiterun, the Helgen Keep Central Room and one of those dog fight dens from bandit forts), a Champion from all settlements (eg. Kynesgrove, Ivarstead, Rorikstead, Solitude) with additional faction champions (from Thalmor, Stormcloak, Forsworn, Imperial, Greybeard, Vigilants, etc.) to battle against, and there'll be a Headsman making sure rules are at play at all times (no poisoning weapons, no magic, no potions, just brutal combat). If the fight goes foul Headsman decapitates both combatants (and you have to reload your save). Just duels, no team fights (yet). Weaponry and armor are balanced (you start with no armor and work your way up, arena is not level dependent and all gear will be "arena leveled" -> you get better armor and weapons with each win), I'll most likely fiddle with Skyrim's combat a bit to make it more suitable for dueling - blocking needs to mitigate damage more but strain stamina and so forth in that manner. It'll be called "Clash of Champions: Prologue" and you'll hear from me soon when the Creation Kit is released and I'll begin on building on the concept. Glad to see I'm not the only one who thought of a proper arena mod.