msem-instigator

Flying, trample

Flying, lifelink
{2}{W}{W}, Exile Archon of Sunrise from your graveyard: Create a token that's a copy of it, except it's an Aura enchantment with enchant creature and “Enchanted creature gets +4/+4 and has flying and lifelink.” Activate only as a sorcery.

Flying
{1}: Archon of Supremacy gets +1/-1 until end of turn.

Flying, menace

Flying, vigilance
As Archon of the Accord enters, choose a number.
Spells with mana value equal to the chosen number can't be cast.

Exile up to three target creatures you control, then return those cards to the battlefield under your control tapped.

When Arcor-Staff Adherent enters, you may remove all -1/-1 counters from target creature.

Create three 2/2 green Wolf creature tokens.

You may choose not to untap Arden, Mirrormage during your untap step.
Whenever Arden becomes untapped or leaves the battlefield, sacrifice all tokens created with it.
{3}{U}, {T}: Create a token that's a copy of another creature on the battlefield.

Wanderlust — When Ardent Explorers enters, if you control four or more differently named lands, create a 1/1 Scout creature token that's all colors. That token gains haste until end of turn.

Kicker {1}{R} (You may pay an additional {1}{R} as you cast this spell.)
Attacking creatures get +2/+0 until end of turn. Those creatures also gain first strike until end of turn if this spell was kicked.

Create a 1/1 red and green Elemental creature token. Creatures you control get +1/+1 and gain haste until end of turn.
Orchestrate {R}{G} (You may exile this card from your hand anytime you could cast a sorcery for its orchestrate cost. When you next resolve a spell, you may cast this from exile without paying its mana cost.)

[+1]: Search your library for a land card, put it onto the battlefield, untap it, then shuffle. Sacrifice a land.
[–2]: Destroy target noncreature permanent. Its controller may search their library for a basic land card, put that card onto the battlefield, then shuffle.
[–6]: Return any number of land cards from your graveyard to the battlefield and untap them. They become 3/3 creatures with haste in addition to their other types.

Whenever Arena Challenger deals damage to a creature, upgrade it. (Give it one of the listed counters it doesn't already have.)
• +1/+1
• First strike
• Prowess

Arid Causeway enters tapped unless you control another Desert.
{T}: Add {R} or {W}.

When Aridland Camaar enters, create a 1/1 white Bird creature token with flying.

If a creature would leave the battlefield this turn, exile it instead.
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, target player sacrifices a creature.

Whenever Arisen Helix attacks, scry 2.
If Arisen Helix would die, exile it instead.

Haste
Whenever Arisen Hunter attacks, target player loses 2 life and you gain 2 life.
If Arisen Hunter would die, exile it instead.

Whenever you cast a noncreature spell, each opponent loses 1 life.
{4}, Exile Arisen Psion from your graveyard: Draw a card.

Whenever Arisen Rider attacks, creatures your opponents control get -1/-1 until end of turn.
If Arisen Rider or another creature or planeswalker would die, exile it instead.

When Arisen Troops dies, you may destroy target creature that was dealt damage this turn.

Trample
Whenever Arisen Tyrant attacks, mill three cards, then you may exile a card from your graveyard. You may cast a copy of the exiled card without paying its mana cost if the spell's mana value is 3 or less.
If Arisen Tyrant would die, exile it instead.

Aristocrat's Gallery enters tapped.
When Aristocrat's Gallery enters, look at the top card of your library. You may put it into your graveyard.
{T}: Add {G} or {U}.

Menace, haste
As long as Arleigh, Spellblade Prodigy is tapped, the first spell you cast during each other player's turn costs {U/R} less to cast. This effect reduces only the amount of colored mana you pay. (For example, if you cast a spell with mana cost {1}{R}, it costs {1} to cast.)