When Oblivion Ring enters the battlefield, exile another target nonland permanent.
When Oblivion Ring leaves the battlefield, return the exiled card to the battlefield under its owner's control.
Pentavus enters the battlefield with five +1/+1 counters on it.
, Remove a +1/+1 counter from Pentavus: Create a 1/1 colorless Pentavite artifact creature token with flying.
, Sacrifice a Pentavite: Put a +1/+1 counter on Pentavus.