Faithless Ronin

Bushido X (X is equal to the number of +1/+1 counters on Faithless Ronin)
Faithless Ronin enters the battlefield with X +1/+1 counters, where X is the mana spent to cast it.
Any player may pay {x} where {x} is at least 1 more than the number of +1/+1 counters on faithless ronin. That player gains control of it and it gains X +1/+1 counters.