Bag of Holding

Whenever you discard a card, exile that card from your graveyard.
{2}, {T}: Draw a card, then discard a card.
{4}, {T}, Sacrifice Bag of Holding: Return all cards exiled with Bag of Holding to their owner's hand.

Safe Haven

{2}, {T}: Exile target creature you control.
At the beginning of your upkeep, you may sacrifice Safe Haven. If you do, return each card exiled with Safe Haven to the battlefield under its owner's control.

Synod Sanctum

{2}, {T}: Exile target permanent you control.
{2}, Sacrifice Synod Sanctum: Return all cards exiled with Synod Sanctum to the battlefield under your control.

Parallax Wave

Fading 5 (This enchantment enters the battlefield with five fade counters on it. At the beginning of your upkeep, remove a fade counter from it. If you can't, sacrifice it.)
Remove a fade counter from Parallax Wave: Exile target creature.
When Parallax Wave leaves the battlefield, each player returns to the battlefield all cards they own exiled with Parallax Wave.