Michael MacRae

"I went through hell to bring you here. It had better be worth it."

Layla Hassan

First strike
When Layla Hassan enters the battlefield and whenever one or more Assassins you control deal combat damage to a player, return target historic card from your graveyard to your hand.

First strike
When Layla Hassan enters and whenever one or more Assassins you control deal combat damage to a player, return target historic card from your graveyard to your hand.

Command Subadjunct

Artifact creatures you control have vigilance.

The Duras Sisters

When The Duras Sisters die, create a 2/1 red Klingon Warrior creature token with haste.

Sanctum Lurker

When this creature enters, empower Jace 1.
Planeswalkers you control aren't put into their owners' graveyards for having 0 loyalty.
Planeswalkers you control have "[+2]: This planeswalker deals 1 damage to each opponent and you gain 1 life."

"Uh, I think I might have overdone it a smidge."
—Ant-Man, Scott Lang

Worlds Within Worlds

Exile all creatures. Each player may put any number of creature cards from their hand onto the battlefield. Then put all cards exiled this way into their owners' hands. Exile Worlds Within Worlds.

Seize the Day

Untap target creature. After this main phase, there is an additional combat phase followed by an additional main phase.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

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.)

"A lot of people told me I could never do this work. I've been proving those people wrong my whole life."

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.)

Nick Fury, Spymaster

First strike
Whenever a creature you control attacks alone, draw a card. Then you may put a creature card with mana value 3 or less from your hand onto the battlefield. It enters tapped and attacking and gains indestructible until end of turn.

One thing is sure: Reed Richards will always overthink things.

Deep Analysis

Target player draws two cards.
Flashback—{1}{U}, Pay 3 life. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Black Widow, Double Agent

Deathtouch
Whenever a creature you control attacks alone, it gains first strike and menace until end of turn. (It can't be blocked except by two or more creatures.)

"Most times, they don't look down until it's too late."

Ant-Man, Scott Lang

"Coulson, I'm in, but the intel was wrong. No, no extraction. This is bigger than we thought!"

Agent 13, Sharon Carter

Whenever a creature you control attacks alone, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")

"I have seen your rightful place. Beneath me."
—Doctor Doom

Aerial Doombot

Flying
Power-up — {5}{U}: Put three +1/+1 counters on this creature. (Activate each power-up ability only once. Reduce the cost by its mana cost if it entered this turn.)

Geometer's Arthropod

Whenever you cast a spell with {X} in its mana cost, look at the top X cards of your library. Put one of them into your hand and the rest on the bottom of your library in a random order.

Decorum Dissertation

Target player draws two cards and loses 2 life.
Paradigm (Then exile this spell. After you first resolve a spell with this name, you may cast a copy of it from exile without paying its mana cost at the beginning of each of your first main phases.)

"Well, well, trying to follow in my footsteps, are you?"

Jecht, Reluctant Guardian // Braska's Final Aeon

Menace
Whenever Jecht deals combat damage to a player, you may exile it, then return it to the battlefield transformed under its owner's control.

Senu, Keen-Eyed Protector

Flying, vigilance
{T}, Exile Senu: You gain 2 life and scry 2.
When a legendary creature you control attacks and isn't blocked, if this card is exiled, put it onto the battlefield attacking.