Mockingbird, Bobbi Morse

Whenever Mockingbird is dealt damage, put a +1/+1 counter on her. (She must survive the damage to get the counter.)

Peggy Carter, Secret Agent

Whenever a creature you control attacks alone, it gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Valkyrior Skyrider

Flying (This creature can't be blocked except by creatures with flying or reach.)
When this creature enters, you gain 4 life.

Wondrous Revival

Return up to three target Hero creature cards from your graveyard to the battlefield.

A.I.M. Bot

Flying (This creature can't be blocked except by creatures with flying or reach.)

Treasure

Killmonger, Ruthless Usurper

Trample
Whenever Killmonger attacks, he gets +1/+0 until end of turn for each artifact defending player controls.
Whenever Killmonger deals combat damage to a player, that player sacrifices an artifact of their choice and you create a Treasure token.

Blue Marvel, Adam Brashear

Flying (This creature can't be blocked except by creatures with flying or reach.)
Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
Whenever you draw your second card each turn, put a +1/+1 counter on Blue Marvel.

Graviton, Fundamental Force

Whenever you draw your second card each turn, choose one —
• Target creature gains flying until end of turn. (It can't be blocked except by creatures with flying or reach.)
• Tap target creature.

Repulsor Bots

Flying (This creature can't be blocked except by creatures with flying or reach.)
When this creature enters, return up to two other target artifacts and/or creatures to their owners' hands.

Stark's Ingenuity

Enchant creature you control
When this Aura enters, you may pay {X}. If you do, draw X cards.
Whenever you draw a card, put a +1/+1 counter on enchanted creature.

Boomerang, Blade Flinger

Whenever Boomerang attacks, he deals 1 damage to each opponent and you gain 1 life.

Doom's Servo-Guards

When this creature enters, you gain 2 life and mill two cards. (Put the top two cards of your library into your graveyard.)

Glamorous Grapplers

Menace (This creature can't be blocked except by two or more creatures.)

Infernal Rebirth

Return one or two target creature cards from your graveyard to your hand.
Basic landcycling {2} ({2}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Madame Hydra, Reanimated

Menace (This creature can't be blocked except by two or more creatures.)
Madame Hydra gets +1/+1 for each creature card in your graveyard.
Whenever Madame Hydra enters or attacks, mill two cards. (Put the top two cards of your library into your graveyard.)

Villain

Minotaur, Roxxon CEO

Whenever Minotaur, Roxxon CEO or another nontoken creature dies, you create a 2/1 black Villain creature token with menace. (It can't be blocked except by two or more creatures.)

Marvel Super Heroes Commander