Jack Kirby

Heroic Intervention

Permanents you control gain hexproof and indestructible until end of turn.

Captain America, Super-Soldier

First strike
Captain America enters with a shield counter on him. (If he would be dealt damage or destroyed, remove a shield counter from him instead.)
As long as Captain America has a shield counter on him, you and other Heroes you control have hexproof.

Three Steps Ahead

Spree (Choose one or more additional costs.)
+ {1}{U} — Counter target spell.
+ {3} — Create a token that's a copy of target artifact or creature you control.
+ {2} — Draw two cards, then discard a card.

Teferi's Protection

Until your next turn, your life total can't change and you gain protection from everything. All permanents you control phase out. (While they're phased out, they're treated as though they don't exist. They phase in before you untap during your untap step.)
Exile Teferi's Protection.

Simulacrum Synthesizer

When this artifact enters, scry 2.
Whenever another artifact you control with mana value 3 or greater enters, create a 0/0 colorless Construct artifact creature token with "This token gets +1/+1 for each artifact you control."

Return to the Ranks

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Return X target creature cards with mana value 2 or less from your graveyard to the battlefield.

Ravenous Tyrannosaurus

Devour 3 (As this creature enters, you may sacrifice any number of creatures. It enters with three times that many +1/+1 counters on it.)
Whenever this creature attacks, it deals damage equal to its power to up to one other target creature. Excess damage is dealt to that creature's controller instead.

No Mercy

Whenever a creature deals damage to you, destroy it.

King T'Challa // Black Panther, Hope Enduring

Flash
Whenever a player draws their second card each turn, you draw a card.
{4}{W}{U}: Transform King T'Challa. Activate only as a sorcery.

Final Act

Choose one or more —
• Destroy all creatures.
• Destroy all planeswalkers.
• Destroy all battles.
• Exile all graveyards.
• Each opponent loses all counters.

Daredevil, Man Without Fear

Vigilance, haste
Radar Sense — You may look at the top card of your library any time.
Whenever you attack, you may exile the top card of your library. If that card is a Hero card, Daredevil gets +2/+1 until end of turn. You may play that card this turn.

Concerted Effort

At the beginning of each upkeep, creatures you control gain flying until end of turn if a creature you control has flying. The same is true for fear, first strike, double strike, landwalk, protection, trample, and vigilance.

Bruce Banner // The Incredible Hulk

{X}{X}, {T}: Draw X cards. Activate only as a sorcery.
{2}{R}{R}{G}{G}: Transform Bruce Banner. Activate only as a sorcery.

Beast Within

Destroy target permanent. Its controller creates a 3/3 green Beast creature token.

Peter Parker // Amazing Spider-Man

When Peter Parker enters, create a 2/1 green Spider creature token with reach.
{1}{G}{W}{U}: Transform Peter Parker. Activate only as a sorcery.