Sightless Brawler

Bestow {4}{W} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)
Sightless Brawler can't attack alone.
Enchanted creature gets +3/+2 and can't attack alone.

Divine Verdict

Destroy target attacking or blocking creature.

Impetuous Sunchaser

Flying, haste
Impetuous Sunchaser attacks each combat if able.

Oppressive Rays

Enchant creature
Enchanted creature can't attack or block unless its controller pays {3}.
Activated abilities of enchanted creature cost {3} more to activate.

Priest of Iroas

{3}{W}, Sacrifice Priest of Iroas: Destroy target enchantment.

Messenger's Speed

Enchant creature
Enchanted creature has trample and haste.

Loyal Pegasus

Flying
Loyal Pegasus can't attack or block alone.

Nyxborn Rollicker

Bestow {1}{R} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)
Enchanted creature gets +1/+1.

Rise to the Challenge

Target creature gets +2/+0 and gains first strike until end of turn.

Mountain

Heliod's Emissary

Bestow {6}{W} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)
Whenever Heliod's Emissary or enchanted creature attacks, tap target creature an opponent controls.
Enchanted creature gets +3/+3.

Spearpoint Oread

Bestow {5}{R} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)
First strike
Enchanted creature gets +2/+2 and has first strike.

Elite Skirmisher

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

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.

Fall of the Hammer

Target creature you control deals damage equal to its power to another target creature.

Plains

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.)

Purphoros's Emissary

Bestow {6}{R} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)
Menace (This creature can't be blocked except by two or more creatures.)
Enchanted creature gets +3/+3 and has menace.

Lightning Strike

Lightning Strike deals 3 damage to any target.

Satyr Rambler

Minotaur Skullcleaver

Haste
When Minotaur Skullcleaver enters, it gets +2/+0 until end of turn.

Arena Athlete

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

Battlewise Valor

Target creature gets +2/+2 until end of turn. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Leonin Snarecaster

When Leonin Snarecaster enters, you may tap target creature.

Ill-Tempered Cyclops

Trample
{5}{R}: Monstrosity 3. (If this creature isn't monstrous, put three +1/+1 counters on it and it becomes monstrous.)