Vault Skirge

({B/P} can be paid with either {B} or 2 life.)
Flying
Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Marrow Shards

({W/P} can be paid with either {W} or 2 life.)
Marrow Shards deals 1 damage to each attacking creature.

Synthesis Pod

({U/P} can be paid with either {U} or 2 life.)
{1}{U/P}, {T}, Exile a spell you control: Target opponent reveals cards from the top of their library until they reveal a card with mana value equal to 1 plus the exiled spell's mana value. Exile that card, then that player shuffles. You may cast that exiled card without paying its mana cost.

Gitaxian Probe

({U/P} can be paid with either {U} or 2 life.)
Look at target player's hand.
Draw a card.

Tezzeret's Gambit

({U/P} can be paid with either {U} or 2 life.)
Draw two cards, then proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Apostle's Blessing

({W/P} can be paid with either {W} or 2 life.)
Target artifact or creature you control gains protection from artifacts or from the color of your choice until end of turn.

Phyrexian Metamorph

({U/P} can be paid with either {U} or 2 life.)
You may have Phyrexian Metamorph enter as a copy of any artifact or creature on the battlefield, except it's an artifact in addition to its other types.

Spellskite

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

Cathedral Membrane

({W/P} can be paid with either {W} or 2 life.)
Defender
When Cathedral Membrane dies during combat, it deals 6 damage to each creature it blocked this combat.

Postmortem Lunge

({B/P} can be paid with either {B} or 2 life.)
Return target creature card with mana value X from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step.

Trespassing Souleater

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

Pith Driller

({B/P} can be paid with either {B} or 2 life.)
When Pith Driller enters, put a -1/-1 counter on target creature.

Spined Thopter

({U/P} can be paid with either {U} or 2 life.)
Flying

K'rrik, Son of Yawgmoth

({B/P} can be paid with either {B} or 2 life.)
Lifelink
For each {B} in a cost, you may pay 2 life rather than pay that mana.
Whenever you cast a black spell, put a +1/+1 counter on K'rrik, Son of Yawgmoth.

Surgical Extraction

({B/P} can be paid with either {B} or 2 life.)
Choose target card in a graveyard other than a basic land card. Search its owner's graveyard, hand, and library for any number of cards with the same name as that card and exile them. Then that player shuffles.

Mental Misstep

({U/P} can be paid with either {U} or 2 life.)
Counter target spell with mana value 1.

Dismember

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

Porcelain Legionnaire

({W/P} can be paid with either {W} or 2 life.)
First strike

Oloro, Ageless Ascetic

At the beginning of your upkeep, you gain 2 life.
Whenever you gain life, you may pay {1}. If you do, draw a card and each opponent loses 1 life.
At the beginning of your upkeep, if Oloro, Ageless Ascetic is in the command zone, you gain 2 life.

Norn's Annex

({W/P} can be paid with either {W} or 2 life.)
Creatures can't attack you or planeswalkers you control unless their controller pays {W/P} for each of those creatures.