msem-instigator

Choose any number —
• Each player loses X life.
• Each player discards X cards.
• Each player sacrifices X creatures.
• Each player sacrifices X lands.

Whenever Slaffield Workgate or another enchantment you control enters, create a 0/2 white Ox creature token.
{3}{W}: Return another target enchantment you control to its owner's hand.

Equipped creature gets +2/+2 and has protection from blue and from black. (It can't be targeted, dealt damage, enchanted, or equipped by anything blue or black.)
Whenever equipped creature deals combat damage to a player, Sword of Fanaticism deals 3 damage to up to one target creature and you gain 3 life.
Equip {R}{W}

Reveal the top five cards of your library. For each card type, you may put a card of that type revealed this way into your hand. Put the rest into your graveyard. Then you may cast a nonland card with mana value 3 or less from your hand without paying its mana cost.

{4}{G}{G}, Exile six other cards from your graveyard: Return Trifold Atrocity from your graveyard to the battlefield with three +1/+1 counters on it. Activate only as a sorcery.

When Indomitable Duo enters, choose up to two creature card names.
Whenever Indomitable Duo attacks, put a +1/+1 counter on each creature you control with a name chosen by Indomitable Duo.

Choose target creature you control. If it has a +1/+1 counter on it, put an additional +1/+1 counter on it. Then it fights target creature you don't control.

Desolate Path enters tapped unless you control one or fewer other lands.
{T}: Add {W} or {B}.
Cycling {2} ({2}, Discard this card: Draw a card.)

When Kessig Wolftamer enters, create a 2/2 green Wolf creature token.
{4}{R}{G}: Transform Kessig Wolftamer. Activate only if it's attacking.

Creatures you control have “{T}: Add {C}.”
Mirage {1}{U} (You may cast this spell as though it had flash for its mirage cost. If you do, sacrifice it at the beginning of the next cleanup step.)

Return target nonland permanent and all other permanents with the same name as that permanent to their owners' hands.
Draw a card.

Trample
When Rosenhulk enters, choose one —
• Create two 0/1 green Plant creature tokens with “{T}: Add {G}.”
• Destroy target artifact or enchantment.
• Rosenhulk fights target creature an opponent controls.

Spend only mana of one color to cast this spell.

Flying
When Aspect of Divinity dies, create a 0/2 red Egg creature token with “When this creature dies, return target creature card with mana value 2 or less from your graveyard to the battlefield.”

Frenzy 1 (Whenever this creature attacks and isn't blocked, it gets +1/+0 until end of turn.)

Target creature you control gets +4/+0 and gains trample until end of turn.

Defender
Whenever another creature you control enters, Orphan of the Nav gets +1/+1 until end of turn and can attack as though it didn't have defender this turn.

This spell costs {1} less to cast for each storied permanent you control. (Enchantments and legendary permanents are storied.)
Counter target spell.
Draw a card.

When Deathless Disciple dies, if it's not a token, create a token that's a copy of it, except it has no mana cost.
Revive {6}{B} ({6}{B}, Exile this card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)

[+1]: Each player discards a card at random, then draws a card.
[–2]: Until end of turn, gain control of target nonland permanent and it gains haste. Untap it.
[–6]: You get an emblem with “Whenever a source you control deals damage to an opponent, gain control of target permanent that player controls.”

Flying, haste
{R}: Varagan Wyrmling gets +1/+0 until end of turn. Activate this ability only up to three times each turn.

Deathtouch
Other creatures you control get -1/-1.
Whenever Mother Night attacks, put target creature card from a graveyard onto the battlefield under your control.

Voracious 1 (As this enters, you may sacrifice an artifact or creature. If you do, it enters with a +1/+1 counter on it.)
At the beginning of combat on your turn, if you sacrificed a permanent this turn, target creature you control gains trample and haste until end of turn.

Haste
Other Elementals you control get +1/+0 and have haste.

If an opponent controls more lands than you, search your library for up to three basic land cards, reveal them, put them into your hand, then shuffle.