Reborn: I think he has Hawkin avatar
Kirinigiri: Former username is Zorocompass and has Kenshin and Kaoru avy
ShadyOjiro: Has chibi Ojiro avatar
MonsterZoro: Has avatar of Zoro and Kyoshiro above Zoro
Fist of Love: Same avatar. King of meme.
Don't know about the rest. Tried to join OJ but couldn't for some reason.