Plains

Cathars' Crusade

Whenever a creature you control enters, put a +1/+1 counter on each creature you control.

Bladed Bracers

Equipped creature gets +1/+1.
As long as equipped creature is a Human or an Angel, it has vigilance.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Pillar of Flame

Pillar of Flame deals 2 damage to any target. If a creature dealt damage this way would die this turn, exile it instead.

Moorland Inquisitor

{2}{W}: This creature gains first strike until end of turn. (It deals combat damage before creatures without first strike.)

Human

Manic Vandal

When this creature enters, destroy target artifact.

Somberwald Vigilante

Whenever this creature becomes blocked by a creature, this creature deals 1 damage to that creature.

Thraben Valiant

Mountain

Benalish Veteran

Whenever this creature attacks, it gets +1/+1 until end of turn.

Zealous Strike

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

Zealous Conscripts

Haste
When this creature enters, gain control of target permanent until end of turn. Untap that permanent. It gains haste until end of turn.

Riot Ringleader

Whenever this creature attacks, Human creatures you control get +1/+0 until end of turn.

Vigilante Justice

Whenever a Human you control enters, this enchantment deals 1 damage to any target.

Thatcher Revolt

Create three 1/1 red Human creature tokens with haste. Sacrifice those tokens at the beginning of the next end step.

Slayers' Stronghold

{T}: Add {C}.
{R}{W}, {T}: Target creature gets +2/+0 and gains vigilance and haste until end of turn.

Pacifism

Enchant creature
Enchanted creature can't attack or block.

Kessig Malcontents

When this creature enters, it deals damage to target player or planeswalker equal to the number of Humans you control.

Goldnight Commander

Whenever another creature you control enters, creatures you control get +1/+1 until end of turn.

Fireball

This spell costs {1} more to cast for each target beyond the first.
Fireball deals X damage divided evenly, rounded down, among any number of targets.

Kruin Striker

Whenever another creature you control enters, this creature gets +1/+0 and gains trample until end of turn. (It can deal excess combat damage to the player or planeswalker it's attacking.)

Banners Raised

Creatures you control get +1/+0 until end of turn.

Incinerate

Incinerate deals 3 damage to any target. A creature dealt damage this way can't be regenerated this turn.

Devout Chaplain

{T}, Tap two untapped Humans you control: Exile target artifact or enchantment.

Commander's Authority

Enchant creature
Enchanted creature has "At the beginning of your upkeep, create a 1/1 white Human creature token."