msem-instigator

Creatures you control get +2/+2 and gain first strike until end of turn.

Choose one —
• Target creature gets +0/+3 until end of turn.
• Target creature gains flying and lifelink until end of turn.

Tribute 2 (As this creature enters, an opponent of your choice may put two +1/+1 counters on it.)
When Leonin Sandfighter enters, if tribute was paid, it gains first strike. Otherwise it gains double strike. (This effect lasts indefinitely.)

Choose target attacking or blocking creature. Scry 3, then reveal the top card of your library. Judge Unworthy deals damage equal to that card's mana value to that creature.

Tribute 1 (As this creature enters, an opponent of your choice may put a +1/+1 counter on it.)
When Giant Dromad enters, if tribute wasn't paid, you may destroy target artifact or enchantment.

Exile target creature.
Draw a card.

Enchant creature
When Eternal Banishment enters, put a +1/+1 counter on enchanted creature.
Remove a +1/+1 counter from enchanted creature: Exile target creature an opponent controls until Eternal Banishment leaves the battlefield. Activate only as a sorcery.

Put a divinity counter on target creature. It gains “This creature has indestructible as long as it has divinity counter on it.” (This effect lasts indefinitely.)

Vigilance
Tribute 3 (As this creature enters, an opponent of your choice may put three +1/+1 counters on it.)
When Dignified Serpent enters, if tribute wasn't paid, put a +1/+1 counter on each other creature you control.

{1}{W}, {T}: Put a +1/+1 counter on target creature without a +1/+1 counter. Activate only as a sorcery.

Reach (This creature can block creatures with flying.)

Enchant creature
Enchanted creature has defender and its activated abilities can't be activated.

Vigilance
Avatar of Utsenchep can block any number of creatures.
All creatures able to block Avatar of Utsenchep do so.

Wise Old Oak enters tapped unless you control a basic Forest.
{T}: Add {G}.
{3}{G}{G}: Until end of turn, Wise Old Oak becomes a 4/4 green Treefolk creature with “Whenever this creature deals combat damage to a player, draw a card.” It's still a land.

Tomb of the Roseblade enters tapped.
{T}: Add {C}.
{X}, {T}, Sacrifice Tomb of the Roseblade: Search your library for an Equipment card with mana value X or less, put it onto the battlefield, then shuffle. Activate only as a sorcery.

Swarming Midden enters tapped unless you control a basic Swamp.
{T}: Add {B}.
{1}{B}{B}: Swarming Midden becomes a 2/3 black Rat creature with menace until end of turn. It's still a land. Whenever it attacks this turn, create a 1/1 black Rat creature token with “This creature can't block.”

Sparring Ground enters with a +1/+1 counter on it.
{T}: Add {C}.
Whenever a creature you control enters, you may move a +1/+1 counter from Sparring Ground onto that creature.

Serene Chapel enters tapped unless you control a basic Plains.
{T}: Add {W}.
{1}{W}{W}: Until end of turn, Serene Chapel becomes a 2/1 white Spirit Cleric creature with flying and “Whenever this creature attacks, you may exile target card from a graveyard.” It's still a land.

As Secluded Courtyard enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type or activate an ability of a creature source of the chosen type.

{T}: Add {C}.
{5}, {T}: Put a +1/+1 counter on target creature you control. Activate only as a sorcery.

Firehearth Halls enters tapped unless you control a basic Mountain.
{T}: Add {R}.
{R}{R}: Firehearth Halls becomes a 1/1 red Dwarf Warrior creature with double strike until end of turn. It's still a land.

Defender, reach

{1}, Sacrifice Traveler's Amulet: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.

Rosesworn Knight gets +1/+1 as long as it's embattled. (A creature is embattled if it has a counter on it or a permanent you control attached to it.)