Najeela, the Blade-Blossom

Whenever a Warrior attacks, you may have its controller create a 1/1 white Warrior creature token that's tapped and attacking.
{W}{U}{B}{R}{G}: Untap all attacking creatures. They gain trample, lifelink, and haste until end of turn. After this phase, there is an additional combat phase. Activate only during combat.

Have

Chulane, Teller of Tales

Vigilance
Whenever you cast a creature spell, draw a card, then you may put a land card from your hand onto the battlefield.
{3}, {T}: Return target creature you control to its owner's hand.

Anafenza, the Foremost

Whenever Anafenza, the Foremost attacks, put a +1/+1 counter on another target tapped creature you control.
If a nontoken creature an opponent owns would die or a creature card not on the battlefield would be put into an opponent's graveyard, exile that card instead.

Soltari Champion

Shadow (This creature can block or be blocked by only creatures with shadow.)
Whenever Soltari Champion attacks, other creatures you control get +1/+1 until end of turn.

Getting

Goblin Wardriver

Battle cry (Whenever this creature attacks, each other attacking creature gets +1/+0 until end of turn.)

Audacious Thief

Whenever Audacious Thief attacks, you draw a card and you lose 1 life.

Wild Beastmaster

Whenever Wild Beastmaster attacks, each other creature you control gets +X/+X until end of turn, where X is Wild Beastmaster's power.

Alesha, Who Smiles at Death

First strike
Whenever Alesha, Who Smiles at Death attacks, you may pay {W/B}{W/B}. If you do, return target creature card with power 2 or less from your graveyard to the battlefield tapped and attacking.

Deathgorge Scavenger

Whenever Deathgorge Scavenger enters the battlefield or attacks, you may exile target card from a graveyard. If a creature card is exiled this way, you gain 2 life. If a noncreature card is exiled this way, Deathgorge Scavenger gets +1/+1 until end of turn.

Nightveil Sprite

Flying
Whenever Nightveil Sprite attacks, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Pianna, Nomad Captain

Whenever Pianna, Nomad Captain attacks, attacking creatures get +1/+1 until end of turn.

Kroxa, Titan of Death's Hunger

When Kroxa enters the battlefield, sacrifice it unless it escaped.
Whenever Kroxa enters the battlefield or attacks, each opponent discards a card, then each opponent who didn't discard a nonland card this way loses 3 life.
Escape—{B}{B}{R}{R}, Exile five other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

Warkite Marauder

Flying
Whenever Warkite Marauder attacks, target creature defending player controls loses all abilities and has base power and toughness 0/1 until end of turn.

Custodi Soulcaller

Melee (Whenever this creature attacks, it gets +1/+1 until end of turn for each opponent you attacked this combat.)
Whenever Custodi Soulcaller attacks, return target creature card with mana value X or less from your graveyard to the battlefield, where X is the number of players you attacked this combat.

Taranika, Akroan Veteran

Vigilance
Whenever Taranika, Akroan Veteran attacks, untap another target creature you control. Until end of turn, that creature has base power and toughness 4/4 and gains indestructible.

Grand Warlord Radha

Haste
Whenever one or more creatures you control attack, add that much mana in any combination of {R} and/or {G}. Until end of turn, you don't lose this mana as steps and phases end.

Krenko, Tin Street Kingpin

Whenever Krenko, Tin Street Kingpin attacks, put a +1/+1 counter on it, then create a number of 1/1 red Goblin creature tokens equal to Krenko's power.

Brimaz, King of Oreskos

Vigilance
Whenever Brimaz, King of Oreskos attacks, create a 1/1 white Cat Soldier creature token with vigilance that's attacking.
Whenever Brimaz blocks a creature, create a 1/1 white Cat Soldier creature token with vigilance that's blocking that creature.

Radha, Heir to Keld

Whenever Radha, Heir to Keld attacks, you may add {R}{R}.
{T}: Add {G}.

Accorder Paladin

Mycosynth Lattice

All permanents are artifacts in addition to their other types.
All cards that aren't on the battlefield, spells, and permanents are colorless.
Players may spend mana as though it were mana of any color.

Captain Lannery Storm

Haste
Whenever Captain Lannery Storm attacks, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
Whenever you sacrifice a Treasure, Captain Lannery Storm gets +1/+0 until end of turn.

Predator Ooze

Indestructible
Whenever Predator Ooze attacks, put a +1/+1 counter on it.
Whenever a creature dealt damage by Predator Ooze this turn dies, put a +1/+1 counter on Predator Ooze.

Geist of Saint Traft

Hexproof (This creature can't be the target of spells or abilities your opponents control.)
Whenever Geist of Saint Traft attacks, create a 4/4 white Angel creature token with flying that's tapped and attacking. Exile that token at end of combat.

Uro, Titan of Nature's Wrath

When Uro enters the battlefield, sacrifice it unless it escaped.
Whenever Uro enters the battlefield or attacks, you gain 3 life and draw a card, then you may put a land card from your hand onto the battlefield.
Escape—{G}{G}{U}{U}, Exile five other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

Tajic, Legion's Edge

Haste
Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)
Prevent all noncombat damage that would be dealt to other creatures you control.
{R}{W}: Tajic, Legion's Edge gains first strike until end of turn.

Signal Pest

Battle cry (Whenever this creature attacks, each other attacking creature gets +1/+0 until end of turn.)
Signal Pest can't be blocked except by creatures with flying or reach.

Mirri, Weatherlight Duelist

First strike
Whenever Mirri, Weatherlight Duelist attacks, each opponent can't block with more than one creature this combat.
As long as Mirri, Weatherlight Duelist is tapped, no more than one creature can attack you each combat.