msem-instigator

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

Creatures you control get +2/+2 and gain vigilance and trample until end of turn.

Whenever another creature you control enters, you may change Declan, Wayward Squire's base power and toughness to that creature's power and toughness until end of turn.

{T}, Sacrifice Decrepit Crags: Search your library for a Swamp or Mountain card and put it onto the battlefield tapped, then shuffle.

Haste
When Dedicated Bushwacker enters, other creatures you control get +1/+0 and gain haste until end of turn.

{T}: Add {G}. If a -1/-1 counter was put on a creature you control this turn, add {G}{G} instead.

Target creature gets +1/+0 and gains first strike until end of turn.
Target creature blocks this turn if able.

Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)
Whenever a player activates an ability of an artifact, creature, or land, if it isn't a mana ability, Dedicated Weaponsmith deals 2 damage to that player.

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.)

At the beginning of your upkeep, choose an opponent. That player creates a 3/2 colorless Horror creature token.
{2}: Target opponent gains control of Deepdrinker's Effigy.

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.

Haste
{R}, Sacrifice Deepstone Operative: Destroy target artifact.

Damage dealt by Deepwater Stinger can't be prevented.

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

Archive 5 (As this enters, shuffle the top five cards of your main library into a new face up library. Sacrifice this after the archived library is empty.)
Whenever you draw a permanent card from the archived library, you may have Defect's Study become a copy of it 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.

Whenever Defective Abomination attacks, you may sacrifice a permanent. If you do, put a +1/+1 counter on it. It gains indestructible until end of turn.

Search your library for a basic land card, reveal it, put it into your hand, then shuffle. Create a 1/1 green Elf creature token.

When Defiant Bristles dies, put a +1/+1 counter on target creature.

Flying

Dekinn, Depths Spirit can't attack or block unless a player has lost 3 or more life this turn.
At the beginning of each player's upkeep, that player may create a Mountain token. If they do, Dekinn deals 3 damage to them.
When Dekinn dies or is put into exile from the battlefield, you may put him into his owner's library third from the top.

Enchant creature
When Delegitimize enters, target opponent sacrifices a land.
Enchanted creature gets +2/+1.

Discard a land card: Target creature can't block this turn.
{R}, Discard a land card: Target creature gets +2/+0 until end of turn.

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.

Target creature gets +5/+5 until end of turn.
Fabled {4}{G} (Then if you cast this for its fabled cost, put it onto the battlefield transformed attached to that creature.)