MTG Boros Aggro Deck by Mirozel1

Eerie — Whenever an enchantment you control enters and whenever you fully unlock a Room, put a +1/+1 counter on target creature.

Valiant — Whenever this creature becomes the target of a spell or ability you control for the first time each turn, put a +1/+1 counter on it. When this creature dies, it deals damage equal to its power to each opponent.

Haste Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.) Valiant — Whenever this creature becomes the target of a spell or ability you control for the first time each turn, exile the top card of your library. Until end of turn, you may play that card.

When this creature enters, discard a card, then draw a card. Delirium — Whenever this creature attacks for the first time each turn, if there are four or more card types among cards in your graveyard, untap target creature. After this phase, there is an additional combat phase.

Offspring {2} (You may pay an additional {2} as you cast this spell. If you do, when this creature enters, create a 1/1 token copy of it.) At the beginning of combat on your turn, target Mouse you control gains your choice of double strike or trample until end of turn.

Haste Whenever this creature is dealt damage, it deals that much damage to any other target. If a player is dealt damage this way, they can't gain life for the rest of the game.

Enchant creature Enchanted creature gets +1/+1 for each enchantment you control and has first strike.

Flash Enchant creature you control As long as this Aura entered this turn, enchanted creature has hexproof. Enchanted creature gets +1/+1.

Enchant creature you control When this Aura enters, exile target nonland permanent an opponent controls until this Aura leaves the battlefield. Enchanted creature gets +1/+0 and has lifelink and ward {2}.

Target creature gets +2/+0 until end of turn. Create a Monster Role token attached to it. (If you control another Role on it, put that one into the graveyard. Enchanted creature gets +1/+1 and has trample.)

If you control two or more other lands, this land enters tapped. {T}: Add {R}. {3}{R}: Until end of turn, this land becomes a 3/2 red Goblin creature with "Whenever this creature attacks, create a 1/1 red Goblin creature token that's tapped and attacking." It's still a land.

({T}: Add {R}.)

{T}: Add {C}. {T}: Add {R} or {W}. This land deals 1 damage to you.

This land enters tapped unless you control two or fewer other lands. {T}: Add {R} or {W}.

({T}: Add {R} or {W}.) As this land enters, you may pay 2 life. If you don't, it enters tapped.

{T}: Add {W}. {T}: Add {R}. Activate only if you control a Mountain or a Plains.