msem-instigator

Whenever a creature enters the battlefield, if it entered from a graveyard or a player cast it from a graveyard, return Ceaseless Stalker from your graveyard to the battlefield at the beginning of the next end step.

Choose one —
• Destroy target artifact.
• Add {R}{R}{R}.

Fiery Temper deals 3 damage to any target.
Madness {R} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Lifelink
Whenever Infectious Ego enters the battlefield or attacks, exile the top card of target opponent's library. If it's a land card, that player gets a poison counter. You may play that card for as long as it remains exiled, and you may spend mana as though it were mana of any color to cast that spell.

Target opponent may draw two cards. If they do, you draw four cards. Otherwise, you create four 1/1 red Elemental creature tokens.

Hexproof
Whenever an enchantment enters the battlefield under your control, draw a card.

Whenever you cast an enchantment spell, you may put target creature on the bottom of its owner's library.

This spell costs {1} less to cast for each artifact and/or enchantment you control.
Trample
Exile a cryptic permanent you control or a cryptic card from your graveyard: Observer of Aeons gets +1/+1 until end of turn. (Artifacts, enchantments, and modal spells are cryptic.)

Hexproof
Invisible Stalker can't be blocked.

Flash
When Axom enters the battlefield, remove up to three counters from target permanent.
{2}{U}: Return Axom to his owner's hand.

[+1]: Haide Bankbuster deals 2 damage divided as you choose among one or two targets.
[+1]: Draw two cards unless any player has Haide Bankbuster deal 3 damage to them.
[–9]: Until end of turn, gain control of all permanents target player controls and they gain haste. Untap those permanents.

(As you complete a condition, decode it. After all are decoded, you solve the mystery and transform this.)
When Mystery of the Crashed Craft enters the battlefield, create a 1/1 red Alien creature token.
{MAG}—You cast an instant spell.
{MAG}—You cast a sorcery spell.

Whenever you cast an instant or sorcery spell, create a 1/1 red Alien creature token.
{2}{R}, Sacrifice two Aliens: Copy target instant or sorcery spell you control. You may choose new targets for the copy.

[+2]: Create a 2/2 red Werewolf creature token with first strike and haste.
[–3]: Tanya deals 3 damage to each creature that's not a Wolf or a Werewolf.
[–8]: For each permanent your opponents control, that player sacrifices it unless they have Tanya deal 2 damage to them.

[+1]: Tanya, the Mooncursed becomes a legendary 3/1 red Werewolf creature with first strike until end of turn.
[–2]: Tanya, the Mooncursed deals 3 damage to target creature or planeswalker.
[–4]: Destroy target nonbasic colorless permanent.

Mountains you control have “{T}: Add {R}{R}.”
[+1]: Exile the top card of your library. You may play that card until the end of your next turn.
[–2]: Conjure six cards named Scorch. Shuffle them and your hand into your library, then draw two cards.

Whenever a player activates an ability that isn't a mana ability, Burning-Tree Shaman deals 1 damage to that player.

Whenever a card is put into a graveyard from anywhere, put a +1/+1 counter on Chief Striking Dawn.
{1}{B}{G}, Remove three counters from Chief Striking Dawn: Return a permanent card from your graveyard to the battlefield.

Whenever Penny and Pete attacks, gain control of up to one target noncreature permanent and up to one target creature until end of turn. Untap the noncreature permanent, then tap the creature. It's attacking.

Each Rogue you control can't be blocked by creatures with greater power than it.
Whenever a Rogue deals combat damage to a player, gain control of target nonland permanent that player controls unless that player pays {1}.

If one or more counters would be put on a permanent you control, you may have that many counters plus one or that many counters minus one put on that permanent instead.

Haste
Whenever Spellslinger Elf deals combat damage to a player, draw a card, then you may cast a card from your hand with mana value 3 or less without paying its mana cost.

Flash
Flying
When Champion of the Provinces enters the battlefield, return any number of other permanents you control to their owner's hands.

Eureka! (At the beginning of each end step, you get a research counter if you cast a spell this turn. Then if you have eight or more research counters, remove them and create a Masterpiece token of your choice.)
{T}: Draw a card, then discard a card.