In Ragnarok Online (iRO), how do you become a ninja? Any builds?

Question

I've been playing RO and I've noticed some people in some strange 'costumes'. I looked it up, and it turns out they're ninjas. I didn't know they were out already. Where and how do you become a ninja, and do you have any stat suggestions or builds?

Answer 1

Can't say for sure, Ninjas are awfully secretive