Jacalt, Wandering Sage

When Jacalt, Wandering Sage enters the battlefield, it explores.
Landfall - Whenever a land enters the battlefield
under your control, you may exile Jacalt,
Wandering Sage with a number of Knowledge counters on it equal to the number of +1/+1
counters on it. On your next end step, return
Jacalt, Wandering Sage to the battlefield with a
number of +1/+1 counters on it equal to the
number of Knowledge counters on it.