msem-instigator

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

Sunlit Fissure enters the battlefield tapped.
{T}: Add {G} or {W}.
{2}{G}{W}: Until end of turn, Sunlit Fissure becomes a 3/5 green and white Elemental creature with with vigilance and “Whenever this creature attacks or blocks, torment yourself.” It's still a land. (To torment yourself, lose 3 life unless you discard a card or sacrifice a nonland permanent.)

As Sunlit Highland enters the battlefield, you may pay 2 life. If you don't, Sunlit Highland enters the battlefield tapped.
{T}, Sacrifice Sunlit Highland: Search your library for a Mountain or Plains card, put it onto the battlefield, then shuffle.

({T}: Add {W}.)
As Sunlit Meadow enters the battlefield, you may pay 1 life. If you don't, Sunlit Meadow enters the battlefield tapped.
Basic lands you control have “{T}: Add {W}.”

({T}: Add {G} or {W}.)
As Sunlit Plaza enters the battlefield, you may pay {1}. If you don't, Sunlit Plaza enters the battlefield tapped.

Sunlit Ruins enters the battlefield tapped unless you control a Swamp.
{T}: Add {G} or {W}.

Flying, haste
Assault {1}{R} (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.)
Whenever one or more +1/+1 counters are put on a creature you control, you may return Sunnula's Firebird from your graveyard to your hand.

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

Equipped creature has “{T}: This creature deals damage equal to its power to any target.”
Equip {4}

Sunrazed Ruins enters the battlefield tapped.
{T}: Add {W}.
{2/W}{2/W}: Sunrazed Ruins becomes a 2/3 white Elemental creature with lifelink until end of turn. It's still a land.

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

Sunrise Orchard enters the battlefield tapped.
{T}: Untap another target land you control.

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

Hexproof
Renown 1 (When this creature deals combat damage to a player, if it isn't renowned, put a +1/+1 counter on it and it becomes renowned.)
As long as Sunrise Sentinel is renowned, other Scouts you control have hexproof.

Sunrise Woods enters the battlefield 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 the battlefield, 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 Monastery enters the battlefield, draw a card, then put a card from your hand on the bottom of your library.
{T}: Add {C}.

Sunspear Surge deals 2 damage to target creature and 1 damage to each other creature.

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

{T}, Pay 1 life: Add {R}.
{T}, Pay 1 life, Sacrifice Sunwashed Spires: Search your library for a Mountain card, put it onto the battlefield tapped, then shuffle.

Haste
At the beginning of your end step, return Sunwatcher Aspirant to its owner's hand.

Enchant creature
Enchanted creature gets +3/+3, has trample, and can only attack alone.