msem-instigator

When Journey to the Zhedina enters, draw a card, then choose a creature card name.
Whenever a creature with the chosen name you control deals damage to a player, put a +1/+1 counter on it.

Put target creature or planeswalker on the bottom of its owner's library. Its controller may scry 1.

Flash
Flying
Legendary creatures you control have flying.

Whenever Journeying Giftbearer or another nontoken creature you control enters, create a green and white Aura enchantment token named Wild Boon attached to that creature. The token has enchant creature and “Enchanted creature gets +1/+1.”

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.

Vigilance

When Joyful Deviant enters or dies, it deals 1 damage to any target.

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.

Draw three cards, then exile three cards from your hand. Until the end of your next turn, you may play those cards.

Whenever a land you control enters, create a 1/1 colorless Servo artifact creature token.
{4}{G}{W}: Put a +1/+1 counter on each creature you control. They gain trample until end of turn.

Concord — This spell costs {2} less to cast if there are four or more card types among permanents you control.
Vigilance (Attacking doesn't cause this creature to tap.)

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.)

Choose target attacking or blocking creature. Scry 3, then reveal the top card of your library. Judge Unworthy deals damage equal to that card's mana value to that creature.

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.

Detain target creature. (Until your next turn, that creature can't attack or block and its activated abilities can't be activated.)
Scry 1.

Flying
Concord — When Judicious Djinni enters, if there are four or more card types among permanents you control, return target instant or sorcery card from your graveyard to your hand.

Menace
Swampcycling {1}, forestcycling {1} ({1}, Discard this card: Search your libary for a Swamp or Forest card, reveal it, put it into your hand, then shuffle.)

{1}{R}: Exile the top card of your library. If it's a creature card, you may play it until the end of your next turn.
{4}{W}: Put two +1/+1 counters on target creature.

Jungle Hollow enters tapped.
When Jungle Hollow enters, you gain 1 life.
{T}: Add {B} or {G}.

Jungle Shrine enters tapped.
{T}: Add {R}, {G}, or {W}.

Return target creature card from your graveyard to your hand. (Then exile this card. You may cast the creature later from exile.)

Return target creature card with mana value 3 or less from your graveyard to the battlefield.

(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.

(Choose only one work as a sorcery to add its ability.)
When Juyu Offering Pool enters, reveal the top five cards of your library. You may put a noncreature card from among them into your hand. Put the rest on the bottom of your library in any order.
{1}{U}: Scales of Shara
Whenever you cast a noncreature spell, put a +1/+1 counter on target creature you control.
{6}{U}{U}: Eye of Shojiro
Whenever you cast a noncreature spell, create an 8/8 blue Kraken creature token.