Santa is a fun guy! He is what I like to call the 'baka boy' of Λucifer. He has a short fuse, and can get riled up and enthusiastic about things. Not really in a violent way, but in an emotional or over-excited way. Santa and Yuki are the ones who first decided to form Λucifer. Santa was in a different band before, but after discovering his girlfriend (the vocalist of that group) in the arms of another guy, he left that band and joined Λucifer. Santa can get jealous and competitive, but not in such a threatening way as Sakuya can get. And as worked up as Santa gets emotionally, he can also just as quickly crash down and be sorry for how he has behaved. HE can show reason, you just have to knock it into him sometimes. ^_-