msem-instigator

Whenever you cast a legendary spell, create a 1/1 white Human creature token.
{W}{U}{B}{R}{G}: Search your library for a legendary card, reveal it, put it into your hand, then shuffle. The next legendary spell you cast this turn costs {W}{U}{B}{R}{G} less to cast.

Menace (This creature can't be blocked except by two or more creatures.)
Engage (This creature must be blocked each combat if able.)

Whenever a card is put into a graveyard from anywhere, put a +1/+1 counter on Chief Striking Dawn.
{1}{B}{G}, Remove three counters from Chief Striking Dawn: Return a permanent card from your graveyard to the battlefield.

Whenever a land you control enters, you may sacrifice a creature. If you do, each opponent sacrifices a creature.
{2}{B}{G}, Sacrifice a land: Draw a card.

Whenever this creature or another creature you control dies, this creature deals 1 damage to each opponent.

Flash
Flying

When Desert Bloom enters, you gain 4 life.
At the beginning of your upkeep, add {G}{G}.

Flying
When Azos enters, each opponent reveals their hand. You choose any number of nonland cards in players' hands and/or creatures on the battlefield with total mana value 7 or less. Exile those cards and/or permanents.

{W}, {T}: Target attacking creature gets +1/+1 until end of turn. This ability costs {W} less to activate if it targets a Soldier.

Lifelink
Whenever a creature without a bounty counter on it dies, you may pay 1 life. When you do, post a bounty on target creature. (Put a bounty counter on that creature. It has “When this creature dies, each opponent draws a card” as long as it has a bounty counter on it.)

Flying
Once each turn, when a creature an opponent controls dies, you may create a Treasure token.
{3}{B/R}{B/R}: Search target opponent's library for a card and exile it face down. Then that player shuffles. You may look at and play that card for as long as it remains exiled. Activate only once each turn and only as a sorcery.

Other Knights and Soldiers you control get +1/+0.
Cowards can't block Knights and Soldiers you control.
When Belmord Bloodcurdler enters, target creature an opponent controls becomes a Coward in addition to its other types. (This effect last indefinitely.)

(Add a quest counter as this enters. Sacrifice after 3.)
Whenever you scry or search your library, add a quest counter.
1 — Target creature you don't control gets -3/-0 until your next turn.
2 — Reveal cards from the top of your library until you reveal a nonland card, then put the revealed cards into your hand.
3 — Reveal the top card of your library. If its mana value is less than or equal to the number of cards in your hand, you may cast it without paying its mana cost.

Cast a copy of target creature or Revelation card in your graveyard without paying its mana cost. If a Revelation is cast this way, it enters as a Horror creature after it resolves.
Exile Wish to See.

Advance {3}{W}{W} (Cast this for {3}{W}{W} to advance it as it enters. {3}{W}{W}: Advance this as a sorcery.)
Whenever Inconspicuous Loxodon advances, search your library for an Equipment card, put it onto the battlefield, then shuffle.
As long as Inconspicuous Loxodon is enchanted or equipped, he's a 5/5 legendary Elephant Rogue named Agent E.

Target opponent discards two cards, then sacrifices a creature.

At the beginning of your upkeep, scry 2.
Reveal the top card of your library: If a creature card with flying was revealed this way, Imperial Chimera gains flying until end of turn. The same is true for first strike, double strike, deathtouch, haste, hexproof, indestructible, lifelink, menace, reach, trample, and vigilance.

(Transform this if it's not attached to a creature. Pay {1}{U} as a sorcery to unattach it.)
Enchant creature you control
Bay-Bandit's Snapper's rider gets +1/+2.
Whenever Bay-Bandit's Snapper's rider deals combat damage to a player, you draw two cards.

Flying
Concord — At the beginning of your upkeep, if there are four or more card types among permanents you control, exile the top card of your library. You may cast that card this turn without paying its mana cost.

{T}: Add {R} or {W}.
{R}{W}, {T}: Target creature gains first strike and haste until end of turn.

{T}: Add {C}.
Tap an untapped creature you control: Dragonwall Gates becomes a 0/4 Wall artifact creature with defender until end of turn. It's still a land.

Haste
You may cast sorcery and enchantment spells as though they had flash.
Whenever you cast an enchantment, instant, or sorcery spell, Lightning-Fast Lionfish gets +1/+0 and gains first strike until end of turn.

Reveal the top five cards of your library. Put one of those cards into your hand. Target opponent chooses two of those cards. Exile the chosen cards, then put the rest into your hand.

Flying

Augmented — At the beginning of each end step, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, put a +1/+1 counter on Defected Explorer.