Arni, Renowned Champion

Trample
Whenever another creature you control enters, Arni gets +X/+0 until end of turn, where X is that creature's power.

Chandra, Torch of Defiance

Chandra, Torch of Defiance Emblem

+1: Exile the top card of your library. You may cast that card. If you don't, Chandra deals 2 damage to each opponent.
+1: Add {R}{R}.
−3: Chandra deals 4 damage to target creature.
−7: You get an emblem with "Whenever you cast a spell, this emblem deals 5 damage to any target."

Gallia, the Merrymaker

Haste
Each other creature you control with a +1/+1 counter on it has haste.
{1}{R}, {T}: Put a +1/+1 counter on target creature that entered this turn.

Jiang Yanggu, Alone

Menace (This creature can't be blocked except by two or more creatures.)
Whenever a creature you control attacks a player alone, discard a card, then draw a card. Then put a +1/+1 counter on that creature for each card you've discarded this turn.

Kiora of Fire and Ashes

Dragon

When Kiora enters, create a 5/5 red Dragon creature token with flying.
{8}: Create a 5/5 red Dragon creature token with flying.

Koth, the Geomancer

Reach
Landfall — Whenever a land you control enters, Koth deals 1 damage to each opponent. If that land is a Mountain, add {R}.

Marwyn, the Clearcutter

{2}, {T}, Sacrifice an artifact or land: Draw a card.

Jace

Countersculpt

As an additional cost to cast this spell, behold a Jace or pay {1}. (To behold a Jace, choose a Jace you control or reveal a Jace card from your hand.)
Counter target spell. Empower Jace 1. (Put a loyalty counter on a Jace token you control. If you don't control one, first create a blue Jace planeswalker token with "[−1]: Surveil 1" and "[−3]: Draw a card.")

Thopter

Pia, Determined Rebuilder

When Pia enters, create a 1/1 colorless Thopter artifact creature token with flying.
{5}{R}: Target creature gets +X/+0 until end of turn, where X is the number of artifacts you control.

Samut, Hazoret's Champion

Tetsuko Umezawa, Pursuer

Double strike
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Whenever a creature an opponent controls with power or toughness 1 or less blocks, Tetsuko Umezawa deals 1 damage to that creature's controller.

Tomik, Izzet Sparkmage

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
If a source you control would deal noncombat damage to an opponent or a permanent an opponent controls, it deals that much damage plus 1 instead.

Way of the Pyromancer

When Way of the Pyromancer enters, empower Jace 2. (Put two loyalty counters on a Jace token you control. If you don't control one, first create a blue Jace planeswalker token with "[−1]: Surveil 1" and "[−3]: Draw a card.")
Planeswalkers you control have "[+1]: Add {R}."

Way of the Warlord

When Way of the Warlord enters, empower Jace 5. (Put five loyalty counters on a Jace token you control. If you don't control one, first create a blue Jace planeswalker token with "[−1]: Surveil 1" and "[−3]: Draw a card.")
Planeswalkers you control have "[−4]: This planeswalker deals 2 damage to up to one target creature or planeswalker and 2 damage to target player."

Winter, Team Player

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Whenever you cast a noncreature spell, creatures you control get +1/+0 until end of turn.

Edgar, Moonlit Sovereign

Flash
At the beginning of your end step, if you didn't cast a spell this turn, put two +1/+1 counters on Edgar.
{4}{G}: Put a +1/+1 counter on each creature you control with a +1/+1 counter on it.

Reality Fracture