msem-instigator

Primal {5}{U}{R} (During your turn, you may cast this spell for {5}{U}{R} instead of playing a land.)
Each player discards their hand, then draws seven cards. If this spell was cast for its primal cost, draw cards equal to the number of cards your opponents discarded this way.

You may put cards with mana value 2 or less that permanents you control explore into your hand as though they were lands. (You won't get the counter if you do.)
Whenever Torch of Those Underfoot attacks, it explores. (Reveal the top card of your library. Put it into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then you may put that card in your graveyard.)

Each player sacrifices three lands. Torment each player three times. (To torment a player, they lose 3 life unless they discard a card or sacrifice a nonland permanent.)

Flying
Ward—{2}, Pay 2 life.
At the beginning of your end step, if a card was put into or left your graveyard this turn, put a +1/+1 counter on Tormentor of Graves.

Glorious end — When Toros the Warchief dies, if it was tapped, return it to the battlefield at the beginning of the next end step.
Attacking creatures you control have deathtouch.

Whenever Tortle Veteran or another Turtle enters the battlefield under your control, that creature explores. (Reveal the top card of your library. Put it into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then you may put that card in your graveyard.)

Flash
When Total Surveillance enters the battlefield, draw a card.
Whenever you cast another spell with flash or an instant, create a 1/1 colorless Drone artifact creature token with flying.

Enchant creature
Enchanted creature gets +3/+3 and has trample.

Mark (Whenever this creature attacks, mark target creature until end of turn.)
Whenever a marked creature dies, target player discards a card.

Rapport — Whenever Trae, Serpent's Grasp and at least one other creature you control become tapped, each player draws a card. Then Trae, Serpent's Grasp deals 2 damage to each opponent with four or more cards in hand.

At the beginning of your end step, choose any number of permanents and/or players, then give each another counter of each kind it already has.
[+1]: Scry 1. Add {U} or {R}.
[–X]: Exile the top X cards of your library. Until end of turn, you may play a card exiled with Trainee Karina Oblay.

Each creature you control enters the battlefield with an additional +1/+1 counter on it.
When Training Sim enters the battlefield, create a Function token with “Target creature you control fights target creature you don't control.” (It's an enchantment. As you cast an instant or sorcery spell, sacrifice any number of Functions to add their effects to that spell.)

Equipped creature gets +2/+2 and has hexproof and vigilance.
Equip {2}

Land creatures you control get +1/+1 and have vigilance.
Enchantment creatures you control get +1/+1 and have lifelink.
Artifact creatures you control get +1/+1 and have flying.

Choose a nonland card name. Search target player's graveyard, hand, and library for any number of cards with that name and exile them. That player shuffles. For each card exiled from their hand this way, you discard a card.

Each player may search their library for a creature card, reveal it, and put it into their hand. Then each player who searched their library this way shuffles it.

Whenever you cast an Aura spell, put two +1/+1 counters on Traveling Thespians.

Once during each of your turns, you may cast an instant, sorcery, or enchantment spell from your graveyard that targets a creature you control.

Creatures you control have “When this creature becomes tapped for the first time during each of your turns, untap it.”
{T}: Add one mana of any color.

When Traversing the Hellwastes enters the battlefield, create a 1/1 green Scout creature token. It gains haste until end of turn.
Whenever a creature enters the battlefield under your control, you may pay 2 life. If you do, draw a card.

Target player sacrifices a creature.
Inscribe {3}{B}{R} ({3}{B}{R}: Exile this card from your hand inscribed on a creature you control. Whenever that creature attacks, its controller may cast a copy of the inscribed card without paying its mana cost. Inscribe only as a sorcery.)

Whenever another nontoken creature enters the battlefield under your control, that creature gains haste until end of turn. Then Tremor Seer deals 1 damage to any target.

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Create a 1/1 red Hound creature token.
II — Create a 4/4 green Rhino Warrior creature token with trample.
III — You may have two target creatures you control fight. If you do and exactly one survives, put four +1/+1 counters on that creature.

Equipped creature gets +1/+0 for each artifact you control.
As long as you control three or more artifacts, equipped creature has flying and haste.
Equip {3}

Erratic, erratic, erratic (When this creature dies, reveal the top four cards of your library. Put a creature card that costs less than this revealed this way onto the battlefield and the rest on the bottom of your library in any order. Repeat this process twice.)