msem-instigator

At the beginning of your upkeep, Reality Collapse deals 1 damage to each opponent.
{2}{R}: Until end of turn, whenever an opponent is dealt noncombat damage, Reality Collapse deals that much damage to target creature that player controls.

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

{T}: Target creature gains haste until end of turn.
{1}{R}, {T}, Sacrifice a Human: Create a token that's a copy of the sacrificed creature, except it's a 3/2 colorless Horror. It gains haste until end of turn. Activate only as a sorcery.

When Recognification Process enters and at the beginning of your upkeep, create a token that's a copy of target artifact you control, then sacrifice an artifact.

Flash
Creatures your opponents control have base power and toughness 1/1.
Fleeting {1}{W}{W} (You may cast this spell for its fleeting cost. If you do, sacrifice it at the beginning of the next end step.)

Choose one —
• Counter target spell unless its controller pays {2}.
• Draw a card.

Choose up to two target permanent cards in your graveyard with total mana value 4 or less. Return one to the battlefield and the rest to your hand.

{2}, Sacrifice Research Aquarium: Draw a card.
When Research Aquarium is put into a graveyard from the battlefield, investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

{1}: Exile target card from a graveyard.
At the beginning of combat on your turn, if there are three or more card types among cards exiled with Respectful Tracker, put a +1/+1 counter on target creature you control.

Choose one —
• Destroy target nonland permanent with mana value less than or equal to the number of card types among cards in your graveyard.
• Return to the battlefield target creature card from your graveyard with mana value less than or equal to the number of card types among permanents you control.

When Restless Explorer enters, search your library for a land card, reveal it, put it into your hand, then shuffle.

Counter target spell.
You may draw four cards. If you do, skip your next turn.

You may cast this spell as though it had flash by sacrificing a creature in addition to its other costs.
Destroy up to four target tapped creatures.

Destroy up to one target artifact, enchantment, or creature with flying. Create two 1/1 green Saproling creature tokens.

When Rigid Conformist enters, for each {W} spent to cast it, create a 1/1 white Human creature token.
Each creature you control gets +2/+2 if you control another creature with the same name as that creature.

At the beginning of combat on your turn, target creature you control gets +1/+0 until end of turn. If you cast two or more spells this turn, it also gains haste and trample until end of turn. If you cast three or more spells this turn, it gets an additional +2/+0 until end of turn.

As Ritual Preparations enters, choose a color.
You don't lose unspent mana of the chosen color as steps and phases end.

When River Miscreants enters, target creature you control can't be blocked this turn.
{2}{U}: Return River Miscreants to its owner's hand. Activate only as a sorcery.

Flash
Enchant creature
When Roar of the Wilds enters, enchanted creature gets +3/+3 until end of turn.
When enchanted creature dies, create a 1/1 green Saproling creature token.

When Rotting Greatwurm dies, put three +1/+1 counters on target creature you control.
Fleeting {2}{G} (You may cast this spell for its fleeting cost. If you do, sacrifice it at the beginning of the next end step.)

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

Once each turn, when Rova, the Fleshweaver enters or you attack with one or more Horrors, you may put a +1/+1 counter on each creature you control. Then if Rova isn't a token, untap each land you control. Until your next turn, you may cast permanent spells as though they had flash.
{2}{G}{G}, Discard Rova: Create a token that's a copy of Rova, the Fleshweaver, except it's 4/4 and isn't legendary. Activate only as a sorcery.

[+1]: Tap target permanent. Put a stun counter on it. (If a permanent with a stun counter would become untapped, remove one from it instead.)
[0]: Put target artifact, instant, or sorcery card from your graveyard on top of your library. If you have an insight counter, you may return that card to your hand instead.
[0]: You get an insight counter.
[–1]: Target creature can't be blocked this turn. Until end of turn, whenever that creature deals damage to an opponent, you draw a card.

When Ruins Entrance enters, exile up to three target cards from graveyards.
{1}, {T}: Exile target card from a graveyard.
{5}, {T}, Sacrifice Ruins Entrance: Return target card from your graveyard to your hand.

Defender, flying
Ruins Guardian can attack as though it didn't have defender as long as a creature died under your control this turn.
Whenever Ruins Guardian attacks, you may exile two creature cards from your graveyard. If you do, draw a card.