Junggeun Yoon

Black Widow, Agile Avenger

Menace
Whenever an opponent draws their second card each turn, put a +1/+1 counter on Black Widow and you draw a card.

Quicksilver, Brash Blur

If Quicksilver, Brash Blur is in your opening hand, you may begin the game with him on the battlefield.
Haste
Power-up — {4}{R}: Put a +1/+1 counter and a double strike counter on Quicksilver. (Activate each power-up ability only once. Reduce the cost by his mana cost if he entered this turn.)

Spider-Man, Web-Spinner

Double strike (This creature deals both first-strike and regular combat damage.)
Haste (This creature can attack and {T} as soon as he comes under your control.)
Whenever Spider-Man attacks, target creature can't block this turn.

"One giant knuckle sandwich, comin' right up!"

Marvelous Melee

Marvelous Melee deals 6 damage to target creature.
Basic landcycling {2} ({2}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Living Lightning, Charged Up

Flying (This creature can't be blocked except by creatures with flying or reach.)
Haste (This creature can attack and {T} as soon as he comes under your control.)
At the beginning of combat on your turn, another target creature you control gets +1/+0 and gains haste until end of turn.

In the arms race to recreate the Super-Soldier Serum, something far more dangerous was let loose on the world.

Extremis Elite

Power-up — {4}{R}: Put two +1/+1 counters on this creature. It deals 1 damage to any target. (Activate each power-up ability only once. Reduce the cost by its mana cost if it entered this turn.)

Big Bertha

Vigilance
Big Bertha enters with X +1/+1 counters on her.
{1}{G}, {T}: Put a +1/+1 counter on Big Bertha.