msem-instigator

As an additional cost to cast this spell, discard a nonland card.
All creatures get -X/-X until end of turn, where X is the discarded card's mana value.

Enchant creature
Enchanted creature is a blue Shaman with base power and toughness 0/2, has “{2}, {T}: Scry 1,” and loses all other abilities.

Scry 2, then reveal the top card of your library. If it's a basic land card, put it onto the battlefield tapped. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom of your library and the rest on top in any order.)

Trample
At the beginning of combat on your turn, create a 1/1 red Lizard Warrior creature token with haste and winnow. (Damage dealt to that token also causes you to lose that much life.)
Whenever Fang of Anaz attacks, it gets +1/+0 for each other attacking Lizard you control until end of turn.

Flying
When Yujei enters, create a 1/1 white Bird creature token with flying.
{2}{W}: Put a +1/+1 counter on another target creature. It gains flying until end of turn. If it already has flying, put a +1/+1 counter on Yujei instead.

Whenever a nontoken creature you control dies, create a 1/1 black and green Citizen creature token and you gain 1 life.

{3}, {T}: Draw a card.
Crew 3 (Tap any number of creatures you control with total power 3 or greater: This Vehicle becomes an artifact creature until end of turn.)

Whenever Current Shaper perseveres, it deals 1 damage to each opponent. (A creature perseveres when it survives damage.)

Enchant creature
Enchanted creature gets +2/+2 and attacks each combat if able.

This spell costs {1} less to cast for each storied permanent you control. (Enchantments and legendary permanents are storied.)
Destroy all nonland, nonstoried permanents.

{T}: Add {C}.
{3}, {T}: Aetherize target permanent you control. Activate only as a sorcery. (To aetherize, create a token that's a copy of it, then exile that token.)

Whenever a land you control enters, untap Ageless Wanderer.
{1}, {T}: Add one mana of any color.

Whenever another creature you control enters, Flightpath Trainee gains flying until end of turn.

Destroy target creature with mana value 2 or less. If it was a token, you gain 2 life.

Put a +1/+1 counter on target creature. Prevent all combat damage other creatures would deal this turn.

Return up to one target creature to its owner's hand. Then if this spell was foretold, you may destroy all creatures.
Foretell {1}{W}{W}{U} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

If a source would deal damage to a creature this turn, prevent all but 1 of that damage.

Whenever Benevolent Host attacks, if you control another Angel or Nephilim, Benevolent Host gains flying until end of turn. Surveil 1.

Search your library for a basic land card, reveal it, put it into your hand, then shuffle.
Amass Soldiers 1. (Put a +1/+1 counter on an Army you control. It's also a Soldier. If you don't control one, create an 0/0 black Soldier Army creature token first.)

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

Enchant creature
When enchanted creature dies, return that card to the battlefield under your control.

Untap all creatures and lands you control during each other player's untap step.
Ascend {4}{R}{R}{R} ({4}{R}{R}{R}: Exile this creature, then return it to the battlefield transformed. Ascend only as a sorcery.)

Whenever a land you control enters, create a 1/1 white Soldier creature token with vigilance.
{4}{G}{W}, Sacrifice Protect the Farm: Creatures you control get +2/+2 until end of turn.

Counter target artifact or sorcery spell.

Reach
Assault {5}{G}{G}{G} (Whenever this attacks, if it has no +1/+1 counters on it, you may pay its assault cost to put a +1/+1 counter on it.)
When Towering Hydraffe assaults, create a token that's a copy of it.