Cryptolith Rite

Creatures you control have "{T}: Add one mana of any color."

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.

Merrow Bonegnawer

{T}: Target player exiles a card from their graveyard.
Whenever you cast a black spell, you may untap Merrow Bonegnawer.

Gitaxian Probe

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

Nighthaze

Target creature gains swampwalk until end of turn. (It can't be blocked as long as defending player controls a Swamp.)
Draw a card.