msem-instigator

This spell can't be countered.
Flying
When Aunor, Dragonsire or another Dragon you control enters, untap target land. That land becomes a 5/5 Dragon creature with flying and haste in addition to its other types.

Enchant creature
When Aura of Leadership enters, create four 1/1 white Human Soldier creature tokens.
Enchanted creature gets +2/+2.

When Auramancer enters, you may return target enchantment card from your graveyard to your hand.

Target player sacrifices an enchantment.
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, return up to one enchantment card from your graveyard to your hand.

When Aureate Golem enters, create a Treasure token. Each other player creates a tapped Treasure token. (They're artifacts with “{T}, Sacrifice this artifact: Add one mana of any color.”)

This spell can't be countered.
Hexproof

Flying
At the beginning of your end step, if you cast no spells this turn, scry 2.

Counter target creature spell. Scry 2.
Foresee — As you draw Aurora's Whisper, you may reveal it and pay {U}. When you do, return target creature with mana value 3 or less to its owner's hand.

Trample
Auspicious Qilin must be blocked if able.

Once each turn, when you cast a noncreature spell, create a 1/1 colorless Human creature token. Put a prowess counter on it.

Whenever you play a land, return a card at random from your graveyard to your hand.
Whenever you cast a green spell, reveal the top card of your library. If it's a land card, put it into your hand. Otherwise, mill it.

Exile target tapped creature. Its controller gains 3 life.

When Automated Blademaster enters, create a colorless Equipment artifact token named Sword with “Equipped creature gets +1/+1” and equip {1} and attach it to Automated Blademaster.

Harmony — Scry 2.
{T}: Harmonize. Activate only as a sorcery. (Trigger up to one harmony of a permanent you control.)

({T}: Add {R} or {G}.)
Autumn Canopy enters tapped.
{1}, {T}: Add {R}{R} or {G}{G}.

Creatures you control get +1/+0 and gain haste until end of turn.

Distribute four +1/+1 counters among up to two target lands you control. Those lands become 0/0 Elemental creatures with haste until end of turn. If you're attacking, tap those lands. They're attacking.
Showcase {3}{R}{G} (Then if you cast this for its showcase cost, create a 1/1 red Bard creature token that can't block and exile this. Whenever it attacks, you may cast a free copy of this.)

Autumn Ward's power and toughness are each equal to the number of creature cards in your graveyard.
Unveil {2}{B}{G} ({2}{B}{G}: Transform this. Unveil only as a sorcery.)

Choose target creature or planeswalker. Its controller may exile it. If that player doesn't, they sacrifice all other creatures and planeswalkers they control.

{T}, Tap an untapped creature you control: You draw a card and you gain 1 life.

When Autumnal Resonants enters, harmonize. (Trigger up to one harmony of a permanent you control.)
Harmony — Create a 3/3 red and green Elemental creature token with haste.

Trample
Harmony — Avalanche Drummer deals 1 damage to any target.
When Avalanche Drummer enters, harmonize. (Trigger up to one harmony of a permanent you control.)

{2}: Add one mana of any color.

Frenzy 2 (Whenever this creature attacks and isn't blocked, it gets +2/+0 until end of turn.)
Blocked creatures you control have first strike.

Flying
Spirited (When this creature enters, you may activate one of its activated abilities without paying its costs.)
{3}{U/B}{U/B}: Look at the top card of target opponent's library, then exile it face down. You may play that card for as long as it remains exiled, and you may spend mana as though it were mana of any type to cast that spell.