msem-instigator

Flash
When Witch of the Veil enters, if it was cast, you may sacrifice a creature. If you do, return that card to the battlefield under its owner's control.

Exile the top two cards of your library. Until end of turn, you may play cards exiled this way. If an instant or sorcery spell cast this way would deal damage to a player or planeswalker, it deals double that damage instead.

Renown 1 (When this creature deals combat damage to a player, if it isn't renowned, put a +1/+1 counter on it and it becomes renowned.)
Whenever a creature you control becomes renowned, you may have it fight target creature you don't control. (Each deals damage equal to its power to the other.)

Trample, haste
Cadence (Whenever you cast a spell, if its mana value is greater than this creature's power, put a +1/+1 counter on this creature.)

During each of your turns, you may cast a copy of a card in an opponent's graveyard by exiling that card in addition to its other costs. (Copies of permanents enter as tokens.)

Draw three cards, then discard two cards unless you discard a multicolored card.

Enchant creature
Enchanted creature must be blocked if able.

Each player can't untap more than one nonbasic land during their untap step.

Vanishing 4 (This permanent enters with four time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
Whenever a time counter is removed from Worship in Vain, discard your hand, then draw a card for each time counter on Worship in Vain.

{R}, Sacrifice Firebelly Toad: It deals 3 damage to target player or planeswalker.

Scry 3. (To scry 3, look at the top three cards of your library, then put any number of them on the bottom of your library and the rest on top in any order.)

Whenever a land you control enters, crystallize.
{10}: Shuffle any number of other permanents you control into their owner's library. Mill that many cards. Put all permanent cards milled this way onto the battlefield. Activate only during your turn and only once each turn.

{T}: Add {C}.
{4}{U}, {T}: Draw a card.
At the beginning of your end step, if you have eight or more cards in your hand, you may pay {5}{U}{U} and exile this land. When you do, take an extra turn after this one.

Enchant creature
When Mystic's Mantle enters, draw a card.
Enchanted creature gets +1/+1.
Mirage {G} (You may cast this spell as though it had flash for its mirage cost. If you do, sacrifice it at the beginning of the next cleanup step.)

Target player mills six cards.
Draw a card.

Primal {2}{R}{R} (During your turn, you may cast this spell for {2}{R}{R} instead of playing a land.)
Flying, prowess
At the beginning of your end step, if you didn't cast a spell this turn, sacrifice Thunderstride.

Wanderlust — When Ardent Explorers enters, if you control four or more differently named lands, create a 1/1 Scout creature token that's all colors. That token gains haste until end of turn.

Subway Shambler can't be blocked by creatures with lesser power.
At the beginning of each end step, if you're horrific, put a +1/+1 counter on Subway Shambler. (You're horrific as long as you've sacrificed a permanent or discarded a card this turn.)

Destroy target artifact, enchantment, or creature with flying.

({T}: Add {G} or {W}.)
Heart of the Glade enters tapped unless you control a basic Forest or a basic Plains.

Exile target creature. If you controlled that creature, create a 4/4 red Dragon creature token with flying. Otherwise, its controller creates a 1/1 white Bird creature token with flying.
Showcase {4}{U} (Then if you cast this for its showcase cost, create a 1/1 red Bard creature token that can't block and exile this. Whenever it attacks, you may cast a free copy of this.)

Target creature gets -3/-3 until end of turn. If you control a legendary creature, instead destroy that creature.

When Razorshell Marauder enters, you may sacrifice a land or exile a land card from your graveyard. When you do, target creature gets -1/-1 until end of turn and can't block this turn.

Remove a -1/-1 counter from target creature. That creature gets +2/+2 until end of turn.

[+1]: For each player, exile the top three cards of that player's library, then put one of those cards into that player's hand.
[0]: Choose target card exiled by Rahit. Until your next turn, you may play that card, and you may spend mana as though it was mana of any type to cast it.
[–7]: Target player draws seven cards.