Battle Arena is a one versus one role playing opportunity. You take take turns and it follows the same rules as this and the guides in the thread linked.
Skin: Black Frost Anivia.
Anivia stood on her two feet, eyeing down a giant door with the words etched onto it, 'Noxus' and then 'Demacia' on one of both doors, above both factions had another faction, which unlike both Demacia and Noxus had golden trimmed letters which bulged out of the wall and those characters together combined into three words, 'The League Of Legends'. Anivia how ever didn't know what currently was going on so she simple watched the letters in awe of how perfect they were, before a weird creak appeared infront of her, she instantly knew that the door was going to open and when it did it opened ever so slightly but the sound that gaped through the small creak was immense, Anivia could'nt even hear the creak anymore but just pure sound of drums, humans and other sounds, she was puzzled for a second before she actually got vision of what was through the door, a sandy Colosseum and with a stride in her step she slowly began moving through the opened door and into a sandy Colosseum at which she stopped in the middle of, looking up and around at the crowd, and with that she grasped the situation with ease, lowering her head towards another door, exactly like the one she just entered through, smiling with an evil laugh "Let the fun begin" Anivia said with a tone of excitement in her voice, crouching down onto the sand before laying down completely, focusing her eyes in the direction of the door before it opened.
This is the intro, you now have to enter the Arena and stand before Anivia. (This is a rule based Colosseum match, so we're doing it step by step).