msem-instigator

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}.

Deathtouch
As long as there are five or more different creature types among creatures you control, Itinerant Stalker gets +1/+0 and must be blocked if able.

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, 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.

When Jade Counterweight enters, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle.
Equipped creature gets +1/+1.
Equip {1}

When Jade Empire Cartographer enters, choose one —
• Surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)
• Put a +1/+1 counter on target creature you control.

This spell costs {1} less to cast for each card type among cards in your graveyard.
Scavenge {4}{G}. This ability costs {1} less to activate for each card type among other cards in your graveyard. ({4}{G}, Exile this card from your graveyard: Put a number of +1/+1 counters equal to this card's power on target creature. Scavenge only as a sorcery.)

All lands gain “{T}: Add one mana of any color” and lose all other abilities.

{1}, {T}: Put a +1/+1 counter on Jade Sentinel. Activate only if you control a creature with power greater than Jade Sentinel's.

{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, you may activate one of its activated abilities without paying its cost.)
{3}{G}, Sacrifice Jade Vault Reclaimer: Destroy target artifact or enchantment.

Equipped creature gets +2/+1.
Equip {2}

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.

Jagged Cairn enters tapped.
{T}: Add {R} or {G}.
{2}{R}{G}, {T}, Sacrifice Jagged Cairn: Draw a card.

{1}, {T}: Tap target creature.

Whenever Jak, Daring Vanguard or another legendary creature you control enters, creatures you control get +1/+0 and gain haste until end of turn.

Lionize {2}{R} ({2}{R}, Exile this card from your hand: Put a +1/+1 counter on target creature and it gains the following abilities until end of turn. You may cast this card on a later turn from exile.)
Double strike

Flying, trample
At the beginning of combat on your turn, goad all creatures with power 3 or less. (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.)
Whenever a creature deals combat damage to an opponent, put a +1/+1 counter on it.

Trample
Other creatures you control have base power and toughness 8/8.

Trample, haste
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.)

You gain 5 life. Then draw a card if you've lost life this turn.

Equipped creature gets +2/+0 and has “{T}, Unattach Javelin: It deals 2 damage to target creature.”
Equip {2}

Trample
Whenever a creature card is put into your graveyard from anywhere, put a +1/+1 counter on Jawbone, Ravenous Mutant.

Enspirit (As you cast this spell, you may exile a nonenchantment creature you control until this leaves the battlefield or fails to resolve. Reduce this spell's cost by the exiled card's mana value.)
{T}: The next creature spell you cast this turn has enspirit. When that creature enters, it becomes an enchantment in addition to its other types.