Plains

Cerodon Yearling

Fresh-Faced Recruit

During your turn, Fresh-Faced Recruit has first strike.

Wojek Halberdiers

Battalion — Whenever Wojek Halberdiers and at least two other creatures attack, Wojek Halberdiers gains first strike until end of turn.

Boros Recruit

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

Duergar Assailant

Sacrifice Duergar Assailant: It deals 1 damage to target attacking or blocking creature.

Martial Glory

Target creature gets +3/+0 until end of turn.
Target creature gets +0/+3 until end of turn.

Scourge of the Nobilis

Enchant creature
As long as enchanted creature is red, it gets +1/+1 and has "{R/W}: This creature gets +1/+0 until end of turn."
As long as enchanted creature is white, it gets +1/+1 and has lifelink. (Damage dealt by the creature also causes its controller to gain that much life.)

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.

Mountain

Flame Slash

Flame Slash deals 4 damage to target creature.

Make Your Mark

Target creature gets +1/+0 until end of turn. When that creature dies this turn, create a 3/2 red and white Spirit creature token.

Rally the Righteous

Radiance — Untap target creature and each other creature that shares a color with it. Those creatures get +2/+0 until end of turn.