Shefet Dunes

{T}: Add {C}.
{T}, Pay 1 life: Add {W}.
{2}{W}{W}, {T}, Sacrifice a Desert: Creatures you control get +1/+1 until end of turn. Activate only as a sorcery.

Moltensteel Dragon

({R/P} can be paid with either {R} or 2 life.)
Flying
{R/P}: This creature gets +1/+0 until end of turn.

Corrupted Crossroads

{T}: Add {C}. ({C} represents colorless mana.)
{T}, Pay 1 life: Add one mana of any color. Spend this mana only to cast a spell with devoid.

Serum Powder

{T}: Add {C}.
Any time you could mulligan and this card is in your hand, you may exile all the cards from your hand, then draw that many cards. (You can do this in addition to taking mulligans.)

Near-Death Experience

At the beginning of your upkeep, if you have exactly 1 life, you win the game.

Trespassing Souleater

{U/P}: This creature can't be blocked this turn. ({U/P} can be paid with either {U} or 2 life.)

Idyllic Tutor

Search your library for an enchantment card, reveal it, put it into your hand, then shuffle.

Dismember

({B/P} can be paid with either {B} or 2 life.)
Target creature gets -5/-5 until end of turn.

Wall of Blood

Defender (This creature can't attack.)
Pay 1 life: This creature gets +1/+1 until end of turn.

Carrion Howler

Pay 1 life: This creature gets +2/-1 until end of turn.

Immolating Souleater

{R/P}: This creature gets +1/+0 until end of turn. ({R/P} can be paid with either {R} or 2 life.)

Pestilent Souleater

{B/P}: This creature gains infect until end of turn. ({B/P} can be paid with either {B} or 2 life. A creature with infect deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Spellskite

{U/P}: Change a target of target spell or ability to this creature. ({U/P} can be paid with either {U} or 2 life.)

Hex Parasite

{X}{B/P}: Remove up to X counters from target permanent. For each counter removed this way, this creature gets +1/+0 until end of turn. ({B/P} can be paid with either {B} or 2 life.)

Insatiable Souleater

{G/P}: This creature gains trample until end of turn. ({G/P} can be paid with either {G} or 2 life.)

Angel's Grace

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
You can't lose the game this turn and your opponents can't win the game this turn. Until end of turn, damage that would reduce your life total to less than 1 reduces it to 1 instead.

Lotus Bloom

Suspend 3—{0} (Rather than cast this card from your hand, pay {0} and exile it with three time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)
{T}, Sacrifice this artifact: Add three mana of any one color.