Kenkyona, Life from Death

At the beginning of each end step, if Kenkyona is
untapped and didn't attack or block this turn,
remove a -1/-1 counter from him and draw a
card. Otherwise, you lose 1 life.
Whenever Kenkyona attacks or blocks, put a
-1/-1 counter on him.
{b/g}{b/g}, Pay 3 life: Kenkyona gains undying until
end of turn. Tap him.