Plains

Abzan Battle Priest

Outlast {W} ({W}, {T}: Put a +1/+1 counter on this creature. Outlast only as a sorcery.)
Each creature you control with a +1/+1 counter on it has lifelink.

Lay Down Arms

Exile target creature with mana value less than or equal to the number of Plains you control. Its controller gains 3 life.

Mentor of the Meek

Whenever another creature you control with power 2 or less enters, you may pay {1}. If you do, draw a card.

Elder Cathar

When Elder Cathar dies, put a +1/+1 counter on target creature you control. If that creature is a Human, put two +1/+1 counters on it instead.

Refuse to Yield

Target creature gets +2/+7 until end of turn. Untap it.

Prowling Felidar

Vigilance
Landfall — Whenever a land you control enters, put a +1/+1 counter on Prowling Felidar.

Kill Shot

Wanderer's Intervention

Wanderer's Intervention deals 4 damage to target attacking or blocking creature.

Abzan Falconer

Outlast {W} ({W}, {T}: Put a +1/+1 counter on this creature. Outlast only as a sorcery.)
Each creature you control with a +1/+1 counter on it has flying.

Relief Captain

When Relief Captain enters, support 3. (Put a +1/+1 counter on each of up to three other target creatures.)

Dog Umbra

Flash
Enchant creature
As long as another player controls enchanted creature, it can't attack or block. Otherwise, Dog Umbra has umbra armor. (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Ainok Bond-Kin

Outlast {1}{W} ({1}{W}, {T}: Put a +1/+1 counter on this creature. Outlast only as a sorcery.)
Each creature you control with a +1/+1 counter on it has first strike.

Last Breath

Exile target creature with power 2 or less. Its controller gains 4 life.

Wall of Omens

Defender
When Wall of Omens enters, draw a card.

Odric's Outrider

Whenever Odric's Outrider or another creature you control dies, put a +1/+1 counter on target creature you control.

Take Up the Shield

Put a +1/+1 counter on target creature. It gains lifelink and indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)