msem-instigator

Flying
As long as it's your turn, creatures you control get +3/+0 and have vigilance.
As long as it's not your turn, creatures you control get +0/+3 and have lifelink.

As Sunflower Fields enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {R}, {G}, or {W}.

Sunken Cavern enters tapped unless another player controls a land that could produce {U} or {R}.
{T}: Add {U} or {R}.

Heretic (Whenever you cast a spell that doesn't share a color with this creature, it gets +1/+1 until end of turn.)
{1}{W}: You gain life equal to Sunken Outcast's power.

Primal {1}{W}{W} (During your turn, you may cast this spell for {1}{W}{W} instead of playing a land.)
Double strike
When Sunken Slasher enters, if you didn't play a land this turn, put a +1/+1 counter on it.

Lifelink
When Sunlight Dancer enters, target opponent gains 4 life.

Haste
Heretic (Whenever you cast a spell that doesn't share a color with this creature, it gets +1/+1 until end of turn.)

Sunny Dunes enters tapped unless another player controls a land that could produce {R} or {W}.
{T}: Add {R} or {W}.

Sunrise Bluffs enters tapped.
{T}: Add {R}.
You may untap Sunrise Bluffs during each other player's untap step. Whenever you do, you lose 1 life.

Sunrise Prairie enters tapped.
{T}: Add {W}.
You may untap Sunrise Prairie during each other player's untap step. Whenever you do, you lose 1 life.

Sunrise River enters tapped.
{T}: Add {U}.
You may untap Sunrise River during each other player's untap step. Whenever you do, you lose 1 life.

Sunrise Ruins enters tapped.
{T}: Add {B}.
You may untap Sunrise Ruins during each other player's untap step. Whenever you do, you lose 1 life.

Sunrise Woods enters tapped.
{T}: Add {G}.
You may untap Sunrise Woods during each other player's untap step. Whenever you do, you lose 1 life.

Sunset Cliffs Hunter gets +1/+0 and has first strike as long as a player controls a permanent with a bounty counter on it.

When Sunset Cliffs Lawman enters, you may 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.)

When Sunset Cliffs Patron enters, you may 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.)

Flash
Flying
When Sunset Herald enters, if it was cast, return to the battlefield all creature cards from your graveyard that were put there from the battlefield this turn.

({T}: Add {W}.)
Sunstage enters tapped.
When Sunstage enters, creatures you control get +0/+1 until end of turn.

Sunwing has flying as long as it's your turn.

Creatures you control get +2/+2 and gain trample until end of turn. If you cast this spell from exile, creatures you control get an additional +2/+2 until end of turn.
Prophecy {2}{G}{G} (Once each turn, you may exile a card with prophecy as you reveal it. When you do, you may cast it for its prophecy cost as long as it's exiled.)

Whenever a creature you control becomes the target of a spell, that creature gets +3/+3 until end of turn.

Primal {1}{G}{G} (During your turn, you may cast this spell for {1}{G}{G} instead of playing a land.)
When Swampedge Sentinel dies, return another creature card from your graveyard to your hand.

At the beginning of combat, each player chooses a creature. Those creatures attack or block this turn if able. Whenever one of those creatures dies this turn, Sweep Stakes deals 3 damage to that creature's controller.

You may tap two untapped red creatures and/or planeswalkers you control with different names rather than pay this spell's mana cost.
Exile the top two cards of your library. Until the end of your next turn, you may play those cards.