Can You Guess Who I Am? Harder Edition

Earlier today I wrote a quick game of "Who am I?"

Everybody guessed right with the answer Clay Guida. Apparently, I made it too easy with my final "hair" clue. So I'm back to stump you guys with a harder version.

I will continue to make things harder until it becomes a necessity to cheat. Although I wish you wouldn't. And if there are already comments, dont scroll down to see evreyones answers, come up with an answer, if your wrong, dont feel bad. I am trying to stump you. I want people to be wrong.

Ground rules are the same:

1. I'll give five clues. As soon as you know who it is, leave your answer in the comments section. Also leave the clue number that made you certain your answer was correct. Be honest. If you don't know, tell me you don't know.
2. In the interest of fairness, use your own knowledge. No Wikipedia, no Sherdog or any other search engine or means of cheating. I am making this list off the top of my own head.
3. If someone has already taken your answer, just agree with them in a response.

Clue 1

I made my MMA debut in 2003, winning my first two fights in the same night.

Clue 2

I have lost just twice in 22 fights, but have never tapped or been knocked out, though I have asked a fight to be stopped.

Clue 3

I made my UFC debut in 2006, winning by unanimous decision over Jason Dent. It was fought in the lightweight division, a division that had been reinstated just five PPV's earlier.

Clue 4

I have two major tattoos, one is tribal, while the other is third step prayer for alcoholics anonymous.

Clue 5

My nickname is Spanish for "The Killer". I share this nickname with a former WBA and WBC boxing champion.

If any more clues are needed, go ahead and say so. Please, don't use Wikipedia or any other forms of cheating, it makes things a lot less fun.

Good luck.