Urdnan, Dromoka Warrior

When Urdnan, Dromoka Warrior enters, put a +1/+1 counter on target creature.
Whenever you attack, target attacking creature with a +1/+1 counter on it gains first strike until end of turn. If that creature has two or more +1/+1 counters on it, it gains double strike until end of turn instead.

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.

Scale Blessing

Bolster 1, then put a +1/+1 counter on each creature you control with a +1/+1 counter on it. (To bolster 1, choose a creature with the least toughness among creatures you control and put a +1/+1 counter on it.)

Oketra's Monument

White creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, create a 1/1 white Warrior creature token with vigilance.

Spirited Companion

When Spirited Companion enters, draw a card.

Anafenza, Kin-Tree Spirit

Whenever another nontoken creature you control enters, bolster 1. (Choose a creature with the least toughness among creatures you control and put a +1/+1 counter on it.)

Dazzling Angel

Flying
Whenever another creature you control enters, you gain 1 life.

Proud Pack-Rhino

When Proud Pack-Rhino enters, choose one —
• Put a shield counter on target permanent. (If it would be dealt damage or destroyed, remove a shield counter from it instead.)
• Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Cenn's Tactician

{W}, {T}: Put a +1/+1 counter on target Soldier creature.
Each creature you control with a +1/+1 counter on it can block an additional creature each combat.

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.

Metastatic Evangel

Whenever another nontoken creature you control enters, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Make a Stand

Creatures you control get +1/+0 and gain indestructible until end of turn. (Damage and effects that say "destroy" don't destroy them.)

Elite Scaleguard

When Elite Scaleguard enters, bolster 2. (Choose a creature with the least toughness among creatures you control and put two +1/+1 counters on it.)
Whenever a creature you control with a +1/+1 counter on it attacks, tap target creature defending player controls.

Envoy of the Ancestors

Outlast {W} ({W}, {T}: Put a +1/+1 counter on this creature. Outlast only as a sorcery.)
Modified creatures you control have lifelink. (Equipment, Auras you control, and counters are modifications.)

Helpful Hunter

Heraldic Banner

As this artifact enters, choose a color.
Creatures you control of the chosen color get +1/+0.
{T}: Add one mana of the chosen color.

Enduring Bondwarden

Backup 1 (When this creature enters, put a +1/+1 counter on target creature. If that's another creature, it gains the following ability until end of turn.)
When this creature dies, put its counters on target creature you control.

Unbounded Potential

Choose one —
• Put a +1/+1 counter on each of up to two target creatures.
• Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)
Entwine {3}{W} (Choose both if you pay the entwine cost.)

Inspiring Paladin

During your turn, this creature has first strike. (It deals combat damage before creatures without first strike.)
During your turn, creatures you control with +1/+1 counters on them have first strike.

Cut a Deal

Each opponent draws a card, then you draw a card for each opponent who drew a card this way.

Kor Cartographer

When Kor Cartographer enters, you may search your library for a Plains card, put it onto the battlefield tapped, then shuffle.

Grateful Apparition

Flying
Whenever Grateful Apparition deals combat damage to a player or planeswalker, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Inspiring Overseer

Flying
When this creature enters, you gain 1 life and draw a card.

Basri's Solidarity

Put a +1/+1 counter on each creature you control.

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.

Soul's Attendant

Whenever another creature enters, you may gain 1 life.

Oreskos Explorer

When Oreskos Explorer enters, search your library for up to X Plains cards, where X is the number of players who control more lands than you. Reveal those cards, put them into your hand, then shuffle.

Soul Warden

Whenever another creature enters, you gain 1 life.

Secret Rendezvous

You and target opponent each draw three cards.

Guardian of the Forgotten

Vigilance
Whenever a modified creature you control dies, manifest the top card of your library. (Equipment, Auras you control, and counters are modifications. To manifest a card, put the top card of your library onto the battlefield face down as a 2/2 creature. Turn it face up any time for its mana cost if it's a creature card.)

Archetype of Courage

Creatures you control have first strike.
Creatures your opponents control lose first strike and can't have or gain first strike.