Master of the Ring enters with an opponent's choice of two different counters on it from among menace, first strike, and trample.

Choose a number between 0 and 5. Counter up to one target spell unless its controller pays {X}, where X is the chosen number. Then mill five minus X cards. You may return a card milled this way to your hand.

Matter Harvester has protection from mana values less than the number of artifacts you control.
Whenever a nonland permanent you don't control leaves the battlefield, create a 1/1 colorless Cyborg artifact creature token.

Target creature you control gets +2/+2 until end of turn. It fights target creature you don't control.

When Meat-Market Heifer is put into a graveyard from anywhere, create a Food token.

Target creature gains indestructible until end of turn. Teach it lifelink.

When Meeting of the Elites enters, create a tapped Treasure token.
You've sacrificed a nonland permanent this turn.

Create two 1/1 blue Wizard creature tokens with prowess.

Equipped creature gets +0/+1 and has vigilance.
Equipped creature assigns combat damage equal to its toughness rather than its power, and can attack as though it didn't have defender.
Equip {2}

Whenever you draw your second card each turn, scry 1 then put a +1/+1 counter on Melancholic Oracle.

When Mellan, Defense Attorney enters, make a pledge.
{T}: Choose a color from among other permanents you control. Another target creature you control gains hexproof from that color until end of turn. It can't be blocked by creatures of that color this turn.

Target artifact or creature's owner puts it on the top or bottom of their library.
Flashback {5}{U}{U}

When Menelaia enters, put a +1/+1 counter on up to three target creatures.
Whenever a creature you control with a counter on it becomes the target of a spell or ability you control, that creature gains hexproof and trample until end of turn.

Flying
{5}: Draw a card. Activate only if your devotion to blue is three or greater.

{3}{W}: Meowsician dares 4.
Whenever a creature you control becomes a Rebel, create a 1/1 white Warrior creature token.

When Merciless Headsman enters, create a 2/2 colorless Minion creature token with decayed.
{1}{B}, Sacrifice another creature: Draw a card.

Trample
Mercurial Wright gets +1/+0 for each other artifact you control.
{2}: Target permanent becomes an artifact in addition to its other types until end of turn.

{1}{U/R}, {T}: Tap target creature, then gain control of it until end of turn. Activate only as a sorcery.

Trample
Creatures you control with trample have “{1}{R}{G}: This creature must be blocked each combat this turn if able.”

Miasmic Cove enters tapped.
{T}: Add {B} or {G}.
{4}{B/G}: Miasmic Cove becomes a 2/3 black and green Snake creature with deathtouch until end of turn. It's still a land. This ability costs {X} less to activate, where X is your devotion to black and green. Activate only once each turn.

Exile the top three cards of your library. You may play up to two of those cards this turn.

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle. Then if you control three or more enchantments, draw a card.

When Minister of Utility enters, make a pledge.
{2}, Sacrifice a Clique: Make a pledge.

Solidarity
When Minoan Engineer dies, create a 1/1 colorless Thopter artifact creature token with flying.

Whenever Minou, the Russet Whisker attacks, you may tap up to one target creature an opponent controls and untap up to one target creature you control. If the creature you control had vigilance, put a +1/+1 counter on it.