msem-instigator

Each creature can't have power greater than its base power and can't have toughness greater than its base toughness.

You can't cast this spell as long as your life total is greater than half your starting life total.
Lifelink
{1}{B}{G}, Discard Death's Widow: Destroy target nonland permanent. You lose life equal to its mana value.

Deathtouch
When Deathbed Confessor enters, if it entered from a graveyard or you cast it from a graveyard, you draw two cards and you lose 2 life.

Flying
Other Spirits you control get +1/+1.
Whenever a Spirit you control attacks, you gain 1 life.

You don't lose the game for having 0 or less life.
Whenever you're dealt damage, mill that many cards.
{B}, Pay 2 life: Put target card in your graveyard on the bottom of your library.

You may exert Deathmarked Explorer as it attacks. When you do, it gets +X/+X until end of turn, where X is 10 minus your life total. (An exerted creature won't untap during your next untap step.)
{T}, Discard a card: Draw a card. Deathmarked Explorer deals 2 damage to you.

Creatures you control have menace.

Whenever a creature you control perseveres, you draw a card and you lose 1 life. (A creature perseveres when it's dealt damage and doesn't die.)
{1}{B}: Deathmask Initiation deals 1 damage to target creature you control.

Menace
When a card leaves your graveyard, exile the top card of your library. You may play that card until the end of your next turn.

Deathwind Survivor's power and toughness are each equal to the number of enchantments you control.
Whenever an enchantment you control enters, put a +1/+1 counter on target creature.

When Debt Dignitary enters, tap target nonland permanent. That permanent doesn't untap during its controller's untap step for as long as you control Debt Dignitary.

Whenever Deceitful Soul becomes blocked by one or more creatures, it gets +2/+0 until end of turn.

When Dedicated Waypoint enters, create a 1/1 white Scout creature token.
{T}: Add {R}, {W}, or {B}.

Enchant creature
Enchanted creature doesn't untap during its controller's untap step.
At the beginning of the upkeep of enchanted creature's controller, that player mills a card.

Exile target creature. Return that card to its owner's hand at the beginning of its owner's next end step.

Flash
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.)

Menace
Creatures you control get +1/+0 as long as you've foretold a card this turn.
Creatures you control get +1/+0 as long as you've cast a foretold spell this turn.

When this creature enters, you may return another target creature you control to its owner's hand. If you do, create a Treasure token.

Reach (This creature can block creatures with flying.)
Whenever Deepwood Spider blocks a creature with flying, Deepwood Spider gains deathtouch until end of turn.

Whenever you cast a spell, if it shared a color with the last spell you cast this turn, put two +1/+1 counters on Defected Android.

Target creature gets +2/+2 and gains flying and lifelink until end of turn.
Orchestrate {W} (You may exile this card from your hand anytime you could cast a sorcery for its orchestrate cost. When you next resolve a spell, you may cast this from exile without paying its mana cost.)

Flash
When Dehmi, Origin Seeker enters, counter target spell an opponent controls unless that spell's controller has you create X 1/1 red Elemental creature tokens, where X is that spell's mana value.

Delusional Noble enters with a -1/-1 counter on it.

Up to three target creatures can't block this turn.
Menagerie — If there are five or more creature types among creatures you control, exile the top three cards of your library. You may play one of those cards until the end of your next turn.

When Demented Brainiac enters and at the beginning of your upkeep, each opponent mills two cards.
{U}, Sacrifice Demented Brainiac: Exile each opponent's graveyard. Until end of turn, you may cast instant and sorcery spells exiled this way, and you may spend mana as though it were mana of any color to cast them.