Brute Force

Target creature gets +3/+3 until end of turn.

Wingsteed Rider

Flying
Heroic — Whenever you cast a spell that targets Wingsteed Rider, put a +1/+1 counter on Wingsteed Rider.

Akroan Crusader

Heroic — Whenever you cast a spell that targets Akroan Crusader, create a 1/1 red Soldier creature token with haste. (It can attack and {T} as soon as it comes under your control.)

Plains

Secluded Steppe

Secluded Steppe enters tapped.
{T}: Add {W}.
Cycling {W} ({W}, Discard this card: Draw a card.)

Rush of Adrenaline

Target creature gets +2/+1 and gains trample until end of turn.

Tethmos High Priest

Heroic — Whenever you cast a spell that targets Tethmos High Priest, return target creature card with mana value 2 or less from your graveyard to the battlefield.

Adamant Will

Target creature gets +2/+2 and gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Forgotten Cave

Forgotten Cave enters tapped.
{T}: Add {R}.
Cycling {R} ({R}, Discard this card: Draw a card.)

Elite Skirmisher

Heroic — Whenever you cast a spell that targets Elite Skirmisher, you may tap target creature.

Satyr Hoplite

Heroic — Whenever you cast a spell that targets Satyr Hoplite, put a +1/+1 counter on Satyr Hoplite.

Mountain

Abraded Bluffs

Abraded Bluffs enters tapped.
When Abraded Bluffs enters, it deals 1 damage to target opponent.
{T}: Add {R} or {W}.

Tenth District Legionnaire

Haste
Whenever you cast a spell that targets Tenth District Legionnaire, put a +1/+1 counter on Tenth District Legionnaire, then scry 1.

Akroan Skyguard

Flying
Heroic — Whenever you cast a spell that targets Akroan Skyguard, put a +1/+1 counter on Akroan Skyguard.

Blazing Crescendo

Target creature gets +3/+1 until end of turn.
Exile the top card of your library. Until the end of your next turn, you may play that card.

Arena Athlete

Heroic — Whenever you cast a spell that targets Arena Athlete, target creature an opponent controls can't block this turn.

Stolen Vitality

Target creature gets +3/+1 until end of turn. If it's your turn, that creature gains trample until end of turn. Otherwise, it gains first strike until end of turn. (A creature with trample can deal excess combat damage to the player or planeswalker it's attacking. A creature with first strike deals combat damage before creatures without first strike.)