Jak and Daxter

Reach, first strike
Whenever a player plainswalks, put an experience counter on Jak and Daxter.
{t}: Remove all non-experience counters from Jak and Daxter, then put X +1/+0, +0/+1, or 1/2X +1/+1 counters on Jak and Daxter where X is the number of experience counters on Jak and Daxter.(rounded up)