Captain America, Team Leader

Whenever another Hero you control enters, it gains vigilance and haste until end of turn. Put a +1/+1 counter on that Hero and a +1/+1 counter on Captain America.

Karn's Bastion

{T}: Add {C}.
{4}, {T}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Island

Sol Ring

Plains

Inventors' Fair

At the beginning of your upkeep, if you control three or more artifacts, you gain 1 life.
{T}: Add {C}.
{4}, {T}, Sacrifice Inventors' Fair: Search your library for an artifact card, reveal it, put it into your hand, then shuffle. Activate only if you control three or more artifacts.

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.

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.)

In the Trenches

Creatures you control get +1/+1.
{5}{W}: Exile target nonland permanent you don't control until this enchantment leaves the battlefield. Activate only as a sorcery and only once.

Iron Man, Titan of Innovation

Flying, haste
Genius Industrialist — Whenever Iron Man attacks, create a Treasure token, then you may sacrifice a noncreature artifact. If you do, search your library for an artifact card with mana value equal to 1 plus the sacrificed artifact's mana value, put it onto the battlefield tapped, then shuffle.

Arcane Signet

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

Jeska's Will

Choose one. If you control a commander as you cast this spell, you may choose both instead.
• Add {R} for each card in target opponent's hand.
• Exile the top three cards of your library. You may play them this turn.

Command Tower

Flawless Maneuver

If you control a commander, you may cast this spell without paying its mana cost.
Creatures you control gain indestructible until end of turn.

Sigarda's Aid

You may cast Aura and Equipment spells as though they had flash.
Whenever an Equipment you control enters, you may attach it to target creature you control.

Commander's Plate

Equipped creature gets +3/+3 and has protection from each color that's not in your commander's color identity.
Equip commander {3}
Equip {5}

Mountain

Sword of War and Peace

Equipped creature gets +2/+2 and has protection from red and from white.
Whenever equipped creature deals combat damage to a player, this Equipment deals damage to that player equal to the number of cards in their hand and you gain 1 life for each card in your hand.
Equip {2}