Jaqen H'gar from the books "A Song of Ice and Fire"
I took reference from the serie "Game of Thrones" for his armor design, I like it!
“The Red God takes what is his, lovely girl. And only death may pay for life. You saved me and the two I was with. You stole three deaths from the Red God. We have to give them back. Speak three names and the man will do the rest. Three lives I will give you - no more, no less, and we're done.”
― George R.R. Martin