translation help
 

can anyone translate in japanese for me "goodbye my little warrior"

I'm suck, so probably its a shit:
さらば、私の小さい戦士！
Saraba, Watashi no chiisai senshi!

I am not sure, here's my version lol.
さよなら、オレの小戦士。
Sayonara, ore no kosenshi

Ohhhh, I don't knew we could combine words : kou + senshi.
Magnific, DragonShade!

That's why I am not sure, you know, sometimes is valid, sometimes not,

I myself would translate it to : さよなら、私（オレ・僕・等等。。）の小さな戦士。
Sayonara, watashi (ore/boku/etc..) no chiisana senshi

Btw...I'm new at japanese but >.< I don't think you can say kosenshi.

but if its a nickname or title, I think you could use combination of kanji, because lots of games I play, they use combination of kanji to title people

Yeah, names/nicknames can use various combinations of kanji so kosenshi is correct if it's a nickame. So I assume it's correct if you meant it as a name rather than separate as a noun and adjective.