Nymin, Hired Assassin

Deathtouch, First Strike, Menace
At the beginning of your upkeep pay {x} where {x} is how many rounds Nymin, Hired Assassin
has been in play.
If you can not pay {x} at the beginning of your
upkeep shuffle Nymin, Hired Assassin back into
your library.
"I can do your dirty business, if you have the right
price."