Observation Altar

At the beginning of your upkeep, place an Observation Counter on a target creature until Observation Altar leaves the field.
{t}: Remove an Observation Counter from
a creature, that creature gains Vigilance.
{t}: Remove two Observation Counters from a creature, give that creature +1/+1 or 0/-1.
{t}: Remove three Observation Counters from a creature, that creature gains Vanishing and 1
Time Counters.