Sentinel Time-Keeper

Sentinel(Attacking doesn't cause this creature to tap,
and it can't be tapped by spells or abilities resolving. It
can still {t} or be tapped as part of paying of a cost.)
Creatures with verse counters on them get +1/+1
for each creature with any verse counters on it.
{u/r}, {t}: Put a verse counter on target permanent.
If you exert Sentinel Time-Keeper, you may put
a verse counter on two more target permanents.