msem-instigator

Whenever Almgrove Ambassador blocks or becomes blocked, you may untap target creature and remove it from combat.

Whenever Almgrove Bladesinger attacks, harmonize. (Trigger up to one harmony of a permanent you control.)
Harmony — Target creature can't block this turn.

First strike
Cadence (Whenever you cast a spell, if its mana value is greater than this creature's power, put a +1/+1 counter on this creature.)
Almgrove Champion can only attack or block alone.

Lifelink
Whenever you cast a spell, harmonize. (Trigger up to one harmony of a permanent you control.)
Harmony — Almgrove Ensemble deals 1 damage to target player or planeswalker.

When Almgrove Librarian enters the battlefield, look at the top card of each of your libraries, then for each of those cards, put it on the top or bottom of one of your libraries.

When Almgrove Performer enters the battlefield, harmonize. (Trigger up to one harmony of a permanent you control.)
Harmony — You gain 3 life.

Defender
Whenever you cast an instant or sorcery spell, you may untap Almgrove Sentinel.
{T}: Almgrove Sentinel deals 1 damage to any target.

Whenever Almgrove Spellblade attacks, harmonize. (Trigger up to one harmony of a permanent you control.)
Harmony — Exile the top two cards of your library. Until end of turn, you may play cards exiled by Almgrove Spellblade.

Enchant creature
Enchanted creature doesn't untap during its controller's untap step.
Enchanted creature loses all abilities except for mana abilities.

Whenever a nontoken creature you control dies, create a 1/1 black Spirit creature token with flying.
[+1]: Each opponent loses 2 life and you gain 2 life.
[–2]: You may sacrifice a creature. When you do, destroy target nonland permanent.

Infamy 1 (Whenever this creature deals combat damage to a player, if it has no +1/+1 counters on it, put a +1/+1 counter on it and it becomes infamous.)
When Alpha Scout becomes infamous, create a 2/2 green Wolf creature token.

Trample
Whenever a creature attacks, Alpha Stag gets +2/+2 until end of turn.

Enchant land
Enchanted land has “{T}: Add one mana of any color.”
{3}, Sacrifice Alpha Trial: Conjure a card named Test Run into your hand. (It's a sorcery that costs {X}{G} with “Create an X/X green Mutant creature token. Draw a card.”)

({T}: Add {G} or {W}.)
Alpine Meadow enters the battlefield tapped.

Alquyut Mount can't attack or block alone.

As Alratha, Pearl of the Sand Sea enters the battlefield, you may have an opponent investigate. If you don't, it enters the battlefield tapped. (To investigate, create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)
{T}: Add {U}.
{1}{U}, {T}: Investigate.

Flying
Whenever an artifact you control leaves the battlefield, scry 1.

Double strike
Whenever an opponent casts a spell that targets you or a spell or permanent you control, Alrathan Outcast deals damage equal to twice its power to that player.
Alrathan Outcast gets +1/+1 for each Aura and Equipment you control.

Whenever Alrathan Scholar deals combat damage to a player or planeswalker, draw a card.
{2}{U}: Target creature gains flying until end of turn.

Flying, prowess
Whenever an artifact enters the battlefield under your control, you may draw a card. If you do, discard a card.

Altar of Adversity enters the battlefield tapped.
{T}: Add {B}.
{T}: Add {R} or {W}. Altar of Adversity doesn't untap during your next untap step unless you control an Angel creature.

Altar of Chaos enters the battlefield tapped.
{T}: Add {R}.
{T}: Add {G} or {U}. Altar of Chaos doesn't untap during your next untap step unless you control an Angel creature.

Altar of Creation enters the battlefield tapped.
{T}: Add {U}.
{T}: Add {B} or {G}. Altar of Creation doesn't untap during your next untap step unless you control an Angel creature.

Altar of Destruction enters the battlefield tapped.
{T}: Add {G}.
{T}: Add {W} or {B}. Altar of Destruction doesn't untap during your next untap step unless you control an Angel creature.