msem-instigator

Creatures you control have “Whenever this creature attacks, put a +1/+1 counter on target creature with lesser power.”
At the beginning of each end step, if there are five or more +1/+1 counters among creatures you control, destroy up to one target artifact or enchantment.

({T}: Add {R} or {G}.)
Whenever Rampant Summit becomes tapped, you lose 1 life unless you control two or more basic lands.

Flying
Whenever you draw a card, put a +1/+1 counter on Acolyte of Life.
Remove two counters from Acolyte of Life: It phases out. (Treat it and anything attached to it as though they don't exist until its controller's next turn.)

This spell costs {1} less to cast for each creature that attacked this turn.
Hot to the Touch deals X damage to any target.

Enchant creature
Enchanted creature can't attack or block, and its activated abilities can't be activated.

When Leery Sortie enters, create two 1/1 green Scout creature tokens.
{R}, Sacrifice Leery Sortie: Target creature can't block this turn.

Target creature gets +1/+3 and gains hexproof until end of turn.

As an additional cost to cast this spell, you may sacrifice a creature.
Create a 1/1 green Insect creature token. If you sacrificed a creature to cast this spell, create three of those tokens instead.

Gain control of target creature until end of turn. Untap it. It gains haste until end of turn.
Rerun (If you cast this from your hand, exile it as it resolves. Whenever a creature you control dies, you may cast this card from exile without paying its mana cost.)

Assault {2}{R}{G} (Whenever this attacks, if it has no +1/+1 counters on it, you may pay its assault cost to put a +1/+1 counter on it.)
When Shemesh assaults, other creatures you control get +2/+2 and gain trample until end of turn.

Flying, vigilance
Exile a creature card from your graveyard: Maligned Scavenger gets +1/+1 until end of turn.

Other Rogues you control have menace.
{2}{U}: Target blocking creature gets -1/-0 until end of turn.

Whenever you cast an instant or sorcery spell, target creature gets +1/+1 until end of turn.

Once each turn, when a creature you control becomes tapped, you may untap that creature and tap up to one target creature.

Whenever a land you control enters, you may have target creature get +1/+0 and gain first strike until end of turn.

{T}: Add one mana of any color.
{1}, {T}: You get a glory counter. (You lose glory counters before life. A player with ten or more glory counters wins the game.)

Flying, vigilance
If a nonland permanent entering the battlefield would cause a triggered ability of a permanent you control to trigger, you may have that ability trigger an additional time. If you do, each opponent copies that ability and may choose new targets for the copies.

Deception {1}{B} ({1}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever Nightfall Infiltrator deals combat damage to a player, that player discards a card.

If you would draw a card, you may instead choose creature or land and exile cards from the top of your library until you exile a card of the chosen kind. Put that card into your hand and put all other cards exiled this way on the bottom of your library in a random order.

Flying, vigilance

Flying
Whenever Olson's Armada attacks, if only one creature crewed it, create a 1/1 white Bird creature token with flying. Otherwise, put a +1/+1 counter on Olson's Armada.
Crew 2 (Tap any number of creatures you control with total power 2 or greater: This Vehicle becomes an artifact creature until end of turn.)

Target player draws a card. Put target spell or nonland permanent that player controls on top of its owner's library.

As an additional cost to cast this spell, put a -1/-1 counter on a creature you control.
Counter target spell.

Damage can't be prevented this turn. Beat & Batter deals 2 damage to target player, then 2 damage to each player that's gained life this turn.

Indestructible
Ghrin-Danu, the Dawnhart can't attack or block unless you control three other creatures with different powers.
Whenever you attack, put a +1/+1 counter on up to one other target creature you control.