Embalmer's Tools

Activated abilities of creature cards in your graveyard cost {1} less to activate.
Tap an untapped Zombie you control: Target player mills a card.

Honor-Worn Shaku

{T}: Add {C}.
Tap an untapped legendary permanent you control: Untap Honor-Worn Shaku.

Energy Tap

Tap target untapped creature you control. If you do, add an amount of {C} equal to that creature's mana value.

Opposition

Tap an untapped creature you control: Tap target artifact, creature, or land.

Dermotaxi

Imprint — As Dermotaxi enters, exile a creature card from a graveyard.
Tap two untapped creatures you control: Until end of turn, Dermotaxi becomes a copy of the exiled card, except it's a Vehicle artifact in addition to its other types.

Relic of Legends

{T}: Add one mana of any color.
Tap an untapped legendary creature you control: Add one mana of any color.

Grimgrin, Corpse-Born

Grimgrin, Corpse-Born enters tapped and doesn't untap during your untap step.
Sacrifice another creature: Untap Grimgrin and put a +1/+1 counter on it.
Whenever Grimgrin attacks, destroy target creature defending player controls, then put a +1/+1 counter on Grimgrin.

Grand Architect

Other blue creatures you control get +1/+1.
{U}: Target artifact creature becomes blue until end of turn.
Tap an untapped blue creature you control: Add {C}{C}. Spend this mana only to cast artifact spells or activate abilities of artifacts.

Cryptic Gateway

Tap two untapped creatures you control: You may put a creature card from your hand that shares a creature type with each creature tapped this way onto the battlefield.

Hair-Strung Koto

Tap an untapped creature you control: Target player mills a card.

Faces of the Past

Whenever a creature dies, tap all untapped creatures that share a creature type with it or untap all tapped creatures that share a creature type with it.

Keldon Battlewagon

Trample
Keldon Battlewagon can't block.
When Keldon Battlewagon attacks, sacrifice it at end of combat.
Tap an untapped creature you control: Keldon Battlewagon gets +X/+0 until end of turn, where X is the power of the creature tapped this way.