msem-instigator

Target creature gains lifelink until end of turn. Untap that creature.
Inscribe {1}{W} ({1}{W}: Exile this card from your hand inscribed on a creature you control. Whenever that creature attacks, its controller may cast a copy of the inscribed card without paying its mana cost. Inscribe only as a sorcery.)

Draw a card.
Inscribe {1}{U} ({1}{U}: Exile this card from your hand inscribed on a creature you control. Whenever that creature attacks, its controller may cast a copy of the inscribed card without paying its mana cost. Inscribe only as a sorcery.)

{T}, Sacrifice a land: Destroy target land.

Whenever you cast your first instant or sorcery spell each turn, untap equipped creature.
Equip {1}

Draw three cards, then you may submerge a card from your hand. (To submerge a card, exile it, then put it on the battlefield face down under its owner's control as a 2/2 creature.)

When Into the Unknown enters the battlefield, create two 1/1 Scout creature tokens that are all colors.
Whenever a land enters the battlefield under your control, if it doesn't have the same name as another land you control, put a +1/+1 counter on each creature you control.

Flying
When Intrepid enters the battlefield, search your library for a land card, reveal it, put it into your hand, then shuffle.
Wanderlust — {0}: Intrepid becomes an artifact creature until end of turn. Activate only if you control four or more differently named lands.

Improve {W} ({W}: Put a +1/+1 counter on this creature. This costs {1} more to activate for each +1/+1 counter on it. Improve only as a sorcery.)
Whenever one or more embattled creatures you control attack, create a 1/1 white Cleric creature token with lifelink. (A creature is embattled if it has a counter on it or has a permanent you control attached to it.)

Create two 1/1 green Elf creature tokens, then up to one target creature gets +X/+X until end of turn, where X is the number of creatures you control. (Targets are chosen before the tokens are created.)

Whenever a creature you control leaves the battlefield, if it had counters on it, you may put one of those counters on Ironpact Marauder.
{1}{B}, Remove two counters from Ironpact Marauder: You draw a card and you lose 1 life.

Melee (Whenever this creature attacks, it gets +1/+1 until end of turn for each opponent you attacked this combat.)

Enchant permanent
Enchanted permanent loses all abilities except for mana abilities and has no name.

Whenever you cast a creature or planeswalker spell, if mana produced by a nonland permanent was spent to cast it, it gains trample and haste until end of turn.
{T}: Add {R} or {G}.

{T}: Izahl, the Stormbringer deals 1 damage to any target.
Whenever you cast a noncreature spell, you may untap target creature you control.

Art of war — At the beginning of your end step, if Jaakuna Betrayer dealt damage to an opponent this turn, you may discard a card. If you do, draw a card.

When Jaakuna Bloodsworn enters the battlefield, any opponent may have it deal 3 damage to them. If a player does, sacrifice Jaakuna Bloodsworn.

Double strike
Art of war — At the beginning of your end step, if Jaakuna Tyrant dealt damage to an opponent this turn, put a +1/+1 counter on it.

{T}: Add {C}.
{T}: Add {C}{C}. You can't spend this mana to cast spells or activate abilities of lands.

Spirited (When this creature enters the battlefield, you may activate one of its activated abilities without paying its cost.)
{3}{G}, Sacrifice Jade Vault Reclaimer: Destroy target artifact or enchantment.

As long as Jadycian Empath is on the battlefield or in your graveyard, it's a land in addition to its other types.
Sacrifice Jadycian Empath: Add one mana of any color.

({T}: Add {R} or {W}.)
Jagged Crag enters the battlefield tapped.

When Jidai Clairvoyant enters the battlefield, create a 2/2 colorless Spirit creature token.
Whenever a colorless creature enters the battlefield under your control, you may draw a card.

This spell costs {1} less to cast for each spell you cast this turn.
When Jidai Serpent enters the battlefield, draw two cards.

Johanna, Skarvith Marshal has first strike as long as it's attacking.
Whenever you attack, you may pay {X}{R/W}{R/W}. When you do, put a +1/+1 counter on each of up to X target attacking creatures. Those creatures gain first strike until end of turn.

When Journey through Kareki enters the battlefield, draw a card, then choose a creature card name.
Creatures you control with the chosen name get +1/+1.