msem-instigator

Other Azra and Demons you control get +1/+1.
As long as you control three or more other Azra and/or Demons, Herald of Tamaak gets +1/+1 and has flying.

Trample, haste
Herald of Untold Riches gets +1/+1 for each color among other spells you've cast this turn.

Flying
{2}{W}, Sacrifice Herald of the Departed: Create two 1/1 white Spirit creature tokens with flying.

Haste
{1}{R}, {T}: Attacking creatures you control get +1/+0 until end of turn.

Vigilance
Creature spells you cast cost {2} less to cast.
Other creatures you control can't attack or block.

Encourage ({T}: Another target creature you control gets +1/+1 until end of turn. Encourage only as a sorcery.)
Whenever a creature deals combat damage to a player, if it was encouraged by Herald of the White Orchid this turn, create a 1/1 white Soldier creature token.

Flying, prowess
Whenever one or more creatures attack, you gain life equal to the greatest power among those creatures.
Whenever you cast a white spell, you may have Heraldry become an Angel creature in addition to its other types or stop being a creature.

You may cast Heralds of Shikai from your graveyard as long as a creature an opponent controls died this turn.

{1}{U}, {T}: Reveal the top card of your library. If it doesn't share a color with Heretical Seer, put it into your hand.

When Hermetic Fisher dies, you may return target creature to its owner's hand.

Hexproof, vigilance, lifelink

Whenever Hero of Aer attacks, it gets +2/+1 until end of turn.

Vigilance
Concord — {G}: Hero of the Stained Blade gets +2/+2 and gains trample until end of turn. Activate only if there are four or more card types among permanents you control and only once each turn.

Whenever Hero's Henchman attacks, another target creature you control gets +1/+1 until end of turn.

Lifelink
Tap three other untapped creatures and/or artifacts you control: Transform Heroic Crusader.

Reach
As long as you control an artifact or an enchantment, Heron's Grace Patrol gets +1/+1 and has vigilance.
{2}{G}{W}, {T}: Mill three cards. You may return a permanent card milled this way to your hand.

First strike, lifelink
Once each turn, when another nontoken creature you control dies, you may create a 2/2 white Elk Spirit creature token with first strike and lifelink named Fawn of Hesediel.

Whenever you cast an instant or sorcery spell, each opponent loses 1 life and you gain 1 life.

{1}{G}, Discard Hibiscus Snapdragon: Create a Treasure token.
Scavenge {4}{G} ({4}{G}, Exile this card from your graveyard: Put a number of +1/+1 counters equal to this card's power on target creature. Scavenge only as a sorcery.)

Encourage ({T}: Another target creature you control gets +1/+1 until end of turn. Encourage only as a sorcery.)
{T}: Add {G}.
Whenever Hierarch Ranger encourages a creature, add one mana of any color.

Whenever a player casts a noncreature spell, create a 1/1 white Human Soldier creature token.
{1}{U}, Tap four untapped creatures you control: Counter target noncreature spell.

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Whenever you cast a noncreature spell, you gain life equal to its mana value.

Whenever High-Priestess Nebti attacks or blocks, create a 2/2 white Cat creature token.
{1}{R}{R}, Tap an untapped Cat creature you control: That creature fights target creature you don't control.

Concord — Highland Hermit gets +1/+1 and has hexproof as long as there are four or more card types among permanents you control.

Flash
If a spell or ability an opponent controls would cause you to discard a creature card, you may put that card onto the battlefield instead.