msem-instigator

This spell costs {1} less to cast for each card in your graveyard.
Menace

Whenever a player casts a spell from their hand, they reveal the top card of their library. If it's a nonland card with a mana value less than that spell's, they may cast it without paying its mana cost. Otherwise, they put it on the bottom of their library.
{2}{U}: Scry 1.

Whenever a nontoken creature you control dies, you may exile it. If you do, create a token that's a copy of it except it's a 1/1 white Spirit creature in addition to its other types and colors.
{2}{B}, Sacrifice a creature: Each opponent loses 1 life and you gain that much life.

Double strike, menace
{R}{W}, Exile Picturesque Champion from your graveyard: Target creature you control gains double strike and menace until end of turn. Activate only as a sorcery.

{T}, Exile a land card from your hand, from your graveyard, or a land that you control: Add one mana of any color.

Foretell {X}{B} (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.)
Target creature gets -X/-X until end of turn. If this spell was foretold, you gain X life.

Whenever you cast a noncreature spell, Prowling Frost-Tiger gets +1/+1 and gains hexproof until end of turn.

First strike
Other creatures you control have protection from mana value 3 or greater.

Creatures you control get +2/+0.
Whenever a creature you control is dealt damage, it deals that much damage to you.

Whenever you cast a noncreature spell, Rageborn Pyromancer gets +1/+1 until end of turn.
{1}{R}: Rageborn Pyromancer gets +1/+0 and gains flying until end of turn.

Up to X target creatures gain winnow until end of turn. (Damage dealt to a creature with winnow also causes its controller to lose that much life.)
Rain of Ruin deals 2 damage to each creature.

Whenever a Plains you control enters, you may put a creature card with mana value 2 or less from your hand onto the battlefield.

Trample
When Reckless Exemplar attacks, if its power is greater than its base power, target creature an opponent controls can't block this turn.

Reckless Rage deals 4 damage to target creature you don't control and 2 damage to target creature you control.

Look at the top two cards of your library. Put one into your graveyard and the other back on top.

Flying, deathtouch
Whenever Risen Raven deals combat damage to a player, draw a card.

Rosesworn Knight gets +1/+1 as long as it's embattled. (A creature is embattled if it has a counter on it or a permanent you control attached to it.)

Flying
Legendary spells you cast cost {1} less to cast.
{W}{U}{B}{R}{G}: Search your library or graveyard for a legendary card, reveal that card, and put it into your hand. If you searched your library this way, shuffle.

Haste
Motley — At the beginning of your upkeep, if there are five or more names among nonland permanents you control, Scarletblood Hound deals 3 damage to each opponent.

Golden age (If you cast an instant or sorcery spell, activated a nonmana ability, and attacked this turn, enter a renaissance for this game.)
Target creature or planeswalker an opponent controls phases out. If you're in a renaissance, exile it instead.

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Create a 0/4 white Wall creature token with defender.
II — Put a +1/+1 counter on up to one target creature.
III — Until your next turn, each creature you control assigns combat damage equal to its toughness rather than its power.

Trample
While you're searching your library, if Shambling Manglers dealt combat damage to an opponent this turn, you may play lands from your library.

Destroy target noncreature permanent.
Memento {5}{G}{G} (You may cast this from your graveyard for {5}{G}{G}. If you do, put it onto the battlefield transformed after it resolves. Exile it if it would leave the battlefield or not resolve.)

Target creature you control deals damage equal to its power to target creature you don't control. For each point of excess damage dealt this way, put a +1/+1 counter on the creature you control.

Frozen Hinterlands enters tapped.
{T}: Add {W} or {B}.
{1}{W}{B}: Until end of turn, Shrouded Rooftops becomes a 3/3 white and black Illusion creature with with lifelink and “Whenever this creature attacks or blocks, torment yourself.” It's still a land. (To torment yourself, lose 3 life unless you discard a card or sacrifice a nonland permanent.)