Hammerhand

Enchant creature
When Hammerhand enters, target creature can't block this turn.
Enchanted creature gets +1/+1 and has haste.

Titan's Strength

Target creature gets +3/+1 until end of turn. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Foundry Street Denizen

Whenever another red creature you control enters, Foundry Street Denizen gets +1/+0 until end of turn.

Rouse the Mob

Strive — This spell costs {2}{R} more to cast for each target beyond the first.
Any number of target creatures each get +2/+0 and gain trample until end of turn.

Frenzied Goblin

Whenever this creature attacks, you may pay {R}. If you do, target creature can't block this turn.

Satyr Hoplite

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

Mountain

Monastery Swiftspear

Haste
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Coordinated Assault

Up to two target creatures each get +1/+0 and gain first strike until end of turn. (They deal combat damage before creatures without first strike.)

Blinding Flare

Strive — This spell costs {R} more to cast for each target beyond the first.
Any number of target creatures can't block this turn.

Uncaged Fury

Target creature gets +1/+1 and gains double strike until end of turn. (It deals both first-strike and regular combat damage.)

Weapon Surge

Target creature you control gets +1/+0 and gains first strike until end of turn.
Overload {1}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

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.)