Oblivion Ring

When this enchantment enters, exile another target nonland permanent.
When this enchantment leaves the battlefield, return the exiled card to the battlefield under its owner's control.

Prophetic Prism

When this artifact enters, draw a card.
{1}, {T}: Add one mana of any color.

Journey to Nowhere

When this enchantment enters, exile target creature.
When this enchantment leaves the battlefield, return the exiled card to the battlefield under its owner's control.

Lembas

When this artifact enters, scry 1, then draw a card.
{2}, {T}, Sacrifice this artifact: You gain 3 life.
When this artifact is put into a graveyard from the battlefield, its owner shuffles it into their library.

Omen of the Sea

Flash (You may cast this spell any time you could cast an instant.)
When this enchantment enters, scry 2, then draw a card.
{2}{U}, Sacrifice this enchantment: Scry 2. (Look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Mulldrifter

Flying
When this creature enters, draw two cards.
Evoke {2}{U} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Peregrine Drake

Flying
When this creature enters, untap up to five lands.

Stonehorn Dignitary

When this creature enters, target opponent skips their next combat phase.

Ichor Wellspring

When this artifact enters or is put into a graveyard from the battlefield, draw a card.

Gilded Pinions

When this Equipment enters, create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")
Equipped creature has flying.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Cryogen Relic

When this artifact enters or leaves the battlefield, draw a card.
{1}{U}, Sacrifice this artifact: Put a stun counter on up to one target tapped creature. (If a permanent with a stun counter would become untapped, remove one from it instead.)

Helpful Hunter

Abdel Adrian, Gorion's Ward

When Abdel Adrian enters, exile any number of other nonland permanents you control until Abdel Adrian leaves the battlefield. Create a 1/1 white Soldier creature token for each permanent exiled this way.
Choose a Background (You can have a Background as a second commander.)

Reality Acid

Enchant permanent
Vanishing 3 (This Aura enters with three time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
When this Aura leaves the battlefield, enchanted permanent's controller sacrifices it.

Gold Pan

When this Equipment enters, create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")
Equipped creature gets +1/+1.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Mnemonic Wall

Defender
When this creature enters, you may return target instant or sorcery card from your graveyard to your hand.

Spirited Companion

Ticket Tortoise

Defender
When this creature enters, if an opponent controls more lands than you, you create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Thought Vessel

You have no maximum hand size.
{T}: Add {C}.

Prized Statue

When this artifact enters or is put into a graveyard from the battlefield, create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Archaeomancer

When this creature enters, return target instant or sorcery card from your graveyard to your hand.

Sailor of Means

When this creature enters, create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Cloud of Faeries

Flying
When this creature enters, untap up to two lands.
Cycling {2} ({2}, Discard this card: Draw a card.)

Burdened Aerialist

When this creature enters, create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")
Whenever you sacrifice a token, this creature gains flying until end of turn.