msem-instigator

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.

[+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.

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

When Arisen Haploc enters, return target creature card from a graveyard to its owner's hand.
Revive {5}{B}{B} ({5}{B}{B}, Exile this card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)

Flying
Whenever a creature you control phases in, it gains flying until end of turn.

Enchant creature
Enchanted creature gets +2/+2 and has trample.
Whenever enchanted creature deals damage, you gain that much life.

Whenever an artifact or enchantment you control enters, Armament Scavenger gets +1/+0 and gains trample until end of turn.

Enchant creature (Target a creature as you cast this. This card enters attached to that creature.)
Enchanted creature gets +2/+2.
{1}{G}: Regenerate enchanted creature.

Reach, vigilance

At the beginning of your end step, you may put a progress counter on Armored Transports.
[PROGRESS 1-2] Creatures you control get +0/+1.
[PROGRESS 3+] Creatures you control get +0/+1 and have vigilance.

When Armored Valiant enters, creatures you control get +1/+1 until end of turn.

Whenever two or more creatures an opponent controls attack, adjudicate. (Create a white Aura enchantment token with enchant creature and “Sacrifice this token: Untap enchanted creature” attached to target creature.)
Enchanted creatures you control get +0/+2.

When Arms Merchant enters, look at the top four cards of your library. You may reveal an artifact card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

Prowess
When Arms Tinkerer enters, choose one —
• Destroy target artifact.
• Create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)

Whenever one or more creatures you control deals combat damage to a player, you may sacrifice one of them. When you do, destroy target creature defending player controls, then you and the destroyed creature's controller draw a card.

Lifelink
When Army's Suppliers enters, recruit. (Create a 0/0 white Soldier Army creature token, then put a +1/+1 counter on each Army you control.)

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
Exile each player's graveyard. Create a token that's a copy of a creature card exiled this way.
Create a token that's a copy of an artifact or enchantment card exiled with Around the Plane in Three Days.
Create a token that's a copy of a land or planeswalker card exiled with Around the Plane in Three Days.

Trample
When Arpechian Bellowers enters, harmonize. (Trigger up to one harmony of a permanent you control.)
Harmony — Search your library for a green creature card, reveal it, put it into your hand, then shuffle.

When Arpechian Groundskeeper enters, rouse 1. (Put a +1/+1 counter on a permanent you control. If it isn't a creature, tap it and it becomes a 0/0 creature in addition to its other types.)
Remove a +1/+1 counter from Arpechian Groundskeeper: Draw a card.

When Arpechian Stag enters, create a 3/3 red Elk creature token with haste, a 3/3 green Elk creature token with trample, and a 3/3 white Elk creature token with vigilance.

Haste
Whenever Arpechian Tiger attacks, you may sacrifice a land. If you do, Arpechian Tiger deals 3 damage to target creature or planeswalker.

Trample
When Arpechian Yatte enters, put a +1/+1 counter on each other creature you control.
Whenever another creature you control enters, put a +1/+1 counter on Arpechian Yatte.