msem-instigator

When Journey through Masamori enters, draw a card, then choose a creature card name.
Creatures you control with the chosen name have “{T}: Add one mana of any color.”

When Journey through Moranai enters, draw a card, then choose a creature card name.
Creatures you control with the chosen name have haste and “{R}: This creature gets +1/+0 until end of turn.”

Look at the top four cards of your library. You may put a land card from among them onto the battlefield tapped. Put the rest into your graveyard.

When Journey to Elrayin enters, journey, then choose a creature card name. (To journey, exile the top card of your library face up. Whenever a creature you control deals combat damage to a player, put a journeyed card you own into your hand.)
Whenever a creature you control with the chosen name deals combat damage to a player, journey.

When Journey to the Otherworlds enters, draw a card, then choose a creature card name.
Whenever a creature you control with the chosen name attacks, you may aetherize it. (To aetherize, create a token that's a copy of it, then exile that token.)

When Journeying Packmaster enters, look at the top card of your library. If it's a land card, you may put it onto the battlefield tapped. If you didn't put that card onto the battlefield, draw a card.

As Joyous Chromatelk enters, choose a color.
All cards that aren't on the battlefield, spells, and permanents are the chosen color in addition to their other colors.
{T}: Add one mana of the chosen color.

Double strike, menace, trample
At the beginning of your end step, sacrifice Juddering Mishap unless you've cast a spell with no creature types this turn. (Noncreature spells have no creature types.)

When Judge of Clans enters, adjudicate. (Create a white enchantment Aura token with enchant creature and “Sacrifice this token: Untap enchanted creature.” attached to target creature.)
{T}: Add one mana of any color.

Judgment of Hao'Tai deals 4 damage to each non-Dragon creature.

When Jumbo Shrimp enters or when you cycle it, destroy target noncreature permanent.
Cycling {3}{G}{G} ({3}{G}{G}, Discard this card: Draw a card.)

Menace
{1}, Discard Jund Shardseeker: Search your library for a basic Swamp or Forest card, reveal it, put it into your hand, then shuffle.

When Junktrawler enters, create a tapped colorless Powercell artifact token with “{T}: Add {C}.”
Tap another untapped artifact you control: Junktrawler gets +1/+1 until end of turn.

(Transcend as a sorcery to gain that type and a +1/+1 counter.)
Jutou enters with X +1/+1 counters on her.
{3}{G}: Demigod — You gain life equal to the greatest power among creatures you control.
{6}{G}: God — Search your library for a creature card with the same power as a creature you control, put it onto the battlefield, then shuffle.

Juvenile Boa gets +2/+0 as long as you control a legendary creature.

Whenever an artifact you control becomes tapped, K-17 Drone deals 1 damage to each opponent.

Kahroba Pureblood has trample as long as it has a counter on it.

Creature spells you cast with power 4 or greater cost {1} less to cast.

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a spell that's three or more colors.

Kalib Kabir has hexproof as long as it has no +1/+1 counters on it.
Kalib Kabir has trample as long as it has a +1/+1 counter on it.
{G}: If Kalib Kabir has a +1/+1 counter on it, remove all +1/+1 counters from it. Otherwise, put a +1/+1 counter on it. Activate only once each turn and only during your turn.

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
When Kalime Charger enters, you may have another target creature you control gain trample until end of turn.

Flying, haste
Ward—Pay 3 life.
The first Dragon spell you cast each turn costs {R}{R} less to cast. (This can reduce the amount of generic mana you pay.)

Equipped creatures you control get +1/+1.
Equip {2}

Destroy target artifact.
Inscribe {2}{R} ({2}{R}: 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.)

As long as it's your turn, Kamito Champion has first strike.
Kamito Champion gets +1/+1 as long as it's equipped, enchanted, or has a card inscribed onto it.