msem-instigator

Forgotten Cryovault enters tapped unless you have two or more opponents.
{T}: Add {U} or {B}.

{T}: Add {C}.
{T}: Add {C}{C}. Spend this mana only to cast spells from your graveyard.

Reveal the bottom card of your library. You may put it on top of your library. Target creature gets -0/-X until end of turn, where X is that card's mana value.

{T}: Add {C}.
{1}, {T}, Sacrifice a creature: Create a 1/1 colorless Spirit creature token.

Put target land card from a graveyard onto the battlefield under your control.

As Forgotten Idol enters, choose a card name.
Spells with the chosen name can't be cast.
{2}, Exile a card with the chosen name from your hand: Exile Forgotten Idol, then each player draws a card. Any player may activate this ability.

Whenever Forgotten King's Mask enters or equipped creature dies, attach it to target creature you control.
Equipped creature has base power and toughness 5/5 and is a Noble in addition to its other types.
{1}{R}, Discard two cards: Create a 1/1 white Human creature token and attach Forgotten King's Mask to it. Activate only as a sorcery.

Search your library for a creature card, an instant card and a sorcery card and reveal them. Put one of those cards into your hand, exile the rest, then shuffle.

Codex — Majestic Dominion; Pristine Dominion; Verdant Dominion; Stalwart Dominion; Primal Dominion; Rugged Dominion; Into the Woods. (As this enters, conjure its contents into a shuffled face-up additional library.)
Before you explore this library, you may put a card from the codex's library on top of it.
{3}{G}: Target creature you control explores.

Return target creature or land card from your graveyard to your hand.

{T}, Pay 1 life: Add {R} or {G}.
{1}, {T}, Sacrifice Forgotten Shrine: Investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Return target creature card from your graveyard to your hand.

({T}: Add {R} or {W}.)
Whenever Forgotten Steppe becomes tapped, you lose 1 life unless you control two or more basic lands.

Archive 3 (As this enters, shuffle the top three cards of your main library into a new face up library. Sacrifice this after the archived library is empty.)
Whenever you draw a card from the archived library, each opponent mills two cards.

{T}: Add {C}. Exile a card from your graveyard.
{3}: Until end of turn, Forgotten Temple becomes an X/X creature, where X is the number of cards exiled by it. It's still a land.
As long as a creature card with flying is exiled by Forgotten Temple, it has flying. The same is true for first strike, double strike, deathtouch, experience, haste, hexproof, indestructible, lifelink, menace, reach, trample, and vigilance.

Forked Pillar deals 2 damage to target creature. When that creature dies this turn, Forked Pillar deals 1 damage to that creature's controller.

Forlorn Path enters tapped unless you control one or fewer other lands.
{T}: Add {B} or {G}.
Cycling {2} ({2}, Discard this card: Draw a card.)

({T}: Add {U} or {B}.)
As Forlorn Ruin enters, you may pay {1}. If you don't, Forlorn Ruin enters tapped.

Target creature you control gets +3/+0 and gains lifelink and indestructible until end of turn.

Enchant creature
Enchanted creature has deathtouch and menace.
{G}{U}: Enchanted creature gains hexproof and indestructible until end of turn. Tap it.
{R}: Enchanted creature gets +1/+0 until end of turn.

Enchant creature
Enchanted creature gets +2/+2 and has flying and haste.
When enchanted creature dies, return it to the battlefield under its owner's control.

When Form of the Sunbird enters, it deals 4 damage to each creature. Your life total becomes 4.
If you would lose the game, instead transform Form of the Sunbird.

Exile target creature you control, then each other player may exile a creature they control. Each player who exiled a creature this way reveals cards from the top of their library until they reveal a creature card with mana value different from the creature they exiled, puts that card onto the battlefield, then shuffles.

Flash
Enchant creature
Enchanted creature has 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.)

Choose any number of target creature and/or planeswalker cards in your graveyard. Return one of them to the battlefield and put the rest on top of your library in any order.