Heartstone

Activated abilities of creatures cost {1} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Mana Flare

Whenever a player taps a land for mana, that player adds one mana of any type that land produced.

Blinkmoth Urn

At the beginning of each player's first main phase, if Blinkmoth Urn is untapped, that player adds {C} for each artifact they control.

Sisay's Ring

Kumano, Master Yamabushi

{1}{R}: Kumano, Master Yamabushi deals 1 damage to any target.
If a creature dealt damage by Kumano this turn would die, exile it instead.

Fire Diamond

Fire Diamond enters tapped.
{T}: Add {R}.

Mana Geyser

Add {R} for each tapped land your opponents control.

Sol Ring

Gorgon's Head

Equipped creature has deathtouch.
Equip {2}

Gorgon Flail

Equipped creature gets +1/+1 and has deathtouch. (Any amount of damage it deals to a creature is enough to destroy that creature.)
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Darksteel Plate

Indestructible
Equipped creature has indestructible.
Equip {2}

Caged Sun

As Caged Sun enters, choose a color.
Creatures you control of the chosen color get +1/+1.
Whenever a land's ability causes you to add one or more mana of the chosen color, add one additional mana of that color.

Star Compass

Star Compass enters tapped.
{T}: Add one mana of any color that a basic land you control could produce.

Pyretic Ritual

Iron Myr

Seething Song

Grafted Exoskeleton

Equipped creature gets +2/+2 and has infect. (It deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Whenever Grafted Exoskeleton becomes unattached from a permanent, sacrifice that permanent.
Equip {2}

Whispersilk Cloak

Equipped creature can't be blocked and has shroud. (It can't be the target of spells or abilities.)
Equip {2}