[Soala]

If you're going for the ninja theme, you could have a name refering to shurikens or part of weapon names, then eventualy mix it with some other letters:

Shuri
Katania

it's up to you to find a name that will appeal people, because I can think about replies you'd get when you say you play RPG Online, like:
-"Ok cool, what RPG?"
or
-"RPG Online? Do you have warriors there?"
-"Nope, ninjas"
-"Eww".