Keeper of Temporal Exile

Whenever a time counter is removed from a card,
put that counter onto Keeper of Temporal Exile. It gets +1/+1 for each time counter on it.

Remove 3 time counters from Keeper of Temporal Exile: Exile a nonland card from your hand with 3 time counters on it. If it doesn't have suspend, it gains suspend.

Whenever a card with suspend is cast from exile,
time travel.