General Ferrous Rokiric

Hexproof from monocolored
Whenever you cast a multicolored spell, create a 4/4 red and white Golem artifact creature token.

Battlegate Mimic

Whenever you cast a spell that's both red and white, Battlegate Mimic has base power and toughness 4/2 until end of turn and gains first strike until end of turn.

Intervention

Intervention deals 3 damage to any target and you gain 3 life.

Integrity

Target creature gets +2/+2 until end of turn.

Integrity // Intervention

Blade Historian

Attacking creatures you control have double strike.

Boros Recruit

({R/W} can be paid with either {R} or {W}.)
First strike

Mountain

Dryad Militant

({G/W} can be paid with either {G} or {W}.)
If an instant or sorcery card would be put into a graveyard from anywhere, exile it instead.

Plains

Heartwarming Redemption

Discard all the cards in your hand, then draw that many cards plus one. You gain life equal to the number of cards in your hand.

Alpine Houndmaster

When Alpine Houndmaster enters, you may search your library for a card named Alpine Watchdog and/or a card named Igneous Cur, reveal them, put them into your hand, then shuffle.
Whenever Alpine Houndmaster attacks, it gets +X/+0 until end of turn, where X is the number of other attacking creatures.

Boros Challenger

Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)
{2}{R}{W}: Boros Challenger gets +1/+1 until end of turn.

Justice Strike

Target creature deals damage to itself equal to its power.

Akroan Hoplite

Whenever Akroan Hoplite attacks, it gets +X/+0 until end of turn, where X is the number of attacking creatures you control.

Aurelia's Fury

Aurelia's Fury deals X damage divided as you choose among any number of targets. Tap each creature dealt damage this way. Players dealt damage this way can't cast noncreature spells this turn.

Lightning Helix

Lightning Helix deals 3 damage to any target and you gain 3 life.

Boros Charm

Choose one —
• Boros Charm deals 4 damage to target player or planeswalker.
• Permanents you control gain indestructible until end of turn.
• Target creature gains double strike until end of turn.