Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)

Graft 2 (This creature enters the battlefield with two +1/+1 counters on it. Whenever another creature enters the battlefield, you may move a +1/+1 counter from this creature onto it.)
: Target creature with a +1/+1 counter on it gains reach until end of turn. (It can block creatures with flying.)

Equip costs you pay cost less.
As long as Auriok Steelshaper is equipped, each creature you control that's a Soldier or a Knight gets +1/+1.

Sacrifice Bile Urchin: Target player loses 1 life.

Tap two untapped Elves you control: Add one mana of any color.
Morph (You may cast this card face down as a 2/2 creature for . Turn it face up any time for its morph cost.)

All Sliver creatures get +2/+0.

All Slivers have ", Sacrifice this permanent: This permanent deals 1 damage to any target."
All Slivers have ", Sacrifice this permanent: Prevent the next 1 damage that would be dealt to target player, planeswalker, or Sliver creature this turn."

Sweep — Return any number of Plains you control to their owner's hand. Creatures you control get +1/+1 until end of turn for each Plains returned this way.

Whenever Chieftain en-Dal attacks, attacking creatures gain first strike until end of turn.

Sunburst (This enters the battlefield with a charge counter on it for each color of mana spent to cast it.)
At the beginning of your upkeep, you may gain life equal to the number of charge counters on Clearwater Goblet.

Counter target spell unless its controller pays .

: Put a charge counter on target artifact.
Sacrifice Coretapper: Put two charge counters on target artifact.

Destroy target artifact, enchantment, or land.

Protection from red
: Target creature gains protection from red until end of turn.

, Sacrifice Daring Apprentice: Counter target spell.

First strike
When Daru Cavalier enters the battlefield, you may search your library for a card named Daru Cavalier, reveal it, and put it into your hand. If you do, shuffle your library.

: Prevent the next 1 damage that would be dealt to any target this turn.
Morph (You may cast this card face down as a 2/2 creature for . Turn it face up any time for its morph cost.)

, Sacrifice a creature: Discard a card, then draw a card.

Enchant creature
Domain — Enchanted creature gets -1/-1 for each basic land type among lands you control.