Head here for more information: http://leagueoflegends.wikia.com/wiki/User_blog:Grrrbear26/Concept_Battle_1.
Oozy's abilities have no cost related to them and their use is limited only by cooldowns. Instead, he uses FURY as his secondary resource. Oozy starts with 0 FURY and it is capped at 100. Oozy gains 5 Fury with each auto-attack, and with the use of some of his abilities. When Oozy has 50 or more FURY, his next ability will consume 50 FURY for an enhanced effect. FURY will decay at a rate of 5 per 2 seconds if Oozy has not dealt or received damage in the last 10 seconds.
With all the wars around Runeterra, some cities and villages were destroyed or turned into ruins. Sometimes a few villagers could survive that, and Oozy was one of those survivors along with his father, Oozy almost lost his mind when he found out about his mother, but his father managed to put his pieces together. They didn't have a place to go, and those wars just made it worse, since not a single city was "respecting" foreigners. Oozy and his father had to become nomads.
Some years later, when most of the wars ceased, they were close to Noxus and decided to ask for a home there, but they had to wait for an answer from the High Command, that would take a few hours and maybe an entire day. On the way to the meeting with a person from the Hight Command, Oozy heard something coming from an alley, but there was nothing there, just some blood marks. Right after that, he saw his father next to him all pale, then his father fell down on the floor, and he could see a dagger stuck on his back. The boy panicked, there was no one else around, but he could hear something, he would never forget that evil laugh. Suddenly he saw a grim face in the shadows, with a finger close to the mouth: "- Shhhhhhh...", and then with a poof it was gone. Oozy's mind went blank, this time he lost it, so he just started laughing hysterically with a soulless look on his face. Talon found him later, and taught him the way of the blade, but Oozy refused to keep learning that, and decided that if he had to fight, he would use some daggers, just like his father's murder weapon. To hide his lunatic look, Talon gave him a mask, but it didn't cover his mouth so everyone could still see his big smile. While he was there, Oozy started to perform around with his daggers, as a juggler and target challenges. One day, he lost his mind once again after seeing the same dagger from his father's murder stuck in a wall, suddenly the people watching him started to look like that shadow with a grim face, and he also could hear it's laugh. He went in a frenzy and killed ten people in a snap throwing his daggers around. After this incident, Talon convinced people to put him in the list to receive a League Judgement, even if Oozy was rejected, it would be safer that way, so they could keep an eye on his actions.
"I don't really trust that kid... But I'm afraid he doesn't either." - Talon
When picking Oozy: "Of all the things I've lost... I miss my mind the most."
Joke: "I can't do anything in moderation." and he burst out laughing.
Taunt: Oozy throws one dagger at the ground saying "I dare you to come and get it" while he is holding another dagger behind him. It has 2 endings, first: he just take the dagger back saying "Thought so."; second: he stabs the air a few times saying "That would be you."
Oozy would HAVE to be the second champion with a non-stop laugh (the first being Jinx ), he would place a hand on his face and start laughing and then burst out laughing placing his hands on his knees.