Kairos, Martial Prodigy

Haste, Double Strike
Flurry of blows: Pay {g}. Choose target creature.
Kairos, Martial Prodigy fights target creature.
Channel Ki: Whenever a creature dies and it
was dealt damage by Kairos on the same turn,
Kairos gets +1/+1 counter.
"That's nice. And... how much did you pay for that?"