Frontline Medic

Battalion — Whenever Frontline Medic and at least two other creatures attack, creatures you control gain indestructible until end of turn.
Sacrifice Frontline Medic: Counter target spell with {X} in its mana cost unless its controller pays {3}.

Boros Cluestone

{T}: Add {R} or {W}.
{R}{W}, {T}, Sacrifice Boros Cluestone: Draw a card.

Boros Elite

Battalion — Whenever Boros Elite and at least two other creatures attack, Boros Elite gets +2/+2 until end of turn.

Warleader's Helix

Warleader's Helix deals 4 damage to any target and you gain 4 life.

Boros Garrison

Boros Garrison enters tapped.
When Boros Garrison enters, return a land you control to its owner's hand.
{T}: Add {R}{W}.

Timely Reinforcements

If you have less life than an opponent, you gain 6 life. If you control fewer creatures than an opponent, create three 1/1 white Soldier creature tokens.