It That Heralds the End

Colorless spells you cast with mana value 7 or greater cost {1} less to cast.
Other colorless creatures you control get +1/+1.

Bane of Bala Ged

Whenever this creature attacks, defending player exiles two permanents they control.

Geier Reach Sanitarium

{T}: Add {C}.
{2}, {T}: Each player draws a card, then discards a card.

Palladium Myr

The Mightstone and Weakstone

When The Mightstone and Weakstone enters, choose one —
• Draw two cards.
• Target creature gets -5/-5 until end of turn.
{T}: Add {C}{C}. This mana can't be spent to cast nonartifact spells.
(Melds with Urza, Lord Protector.)

Nexus of Becoming

At the beginning of combat on your turn, draw a card. Then you may exile an artifact or creature card from your hand. If you do, create a token that's a copy of the exiled card, except it's a 3/3 Golem artifact creature in addition to its other types.

Thespian's Stage

{T}: Add {C}.
{2}, {T}: This land becomes a copy of target land, except it has this ability.

The Eternity Elevator

{T}: Add {C}{C}{C}.
Station (Tap another creature you control: Put charge counters equal to its power on this Spacecraft. Station only as a sorcery.)
20+ | {T}: Add X mana of any one color, where X is the number of charge counters on The Eternity Elevator.

Quicksilver Amulet

{4}, {T}: You may put a creature card from your hand onto the battlefield.

Inspiring Statuary

Nonartifact spells you cast have improvise. (Your artifacts can help cast those spells. Each artifact you tap after you're done activating mana abilities pays for {1}.)

Selective Obliteration

Each player chooses a color. Then exile each permanent unless it's colorless or it's only the color its controller chose.

Endbringer

Untap this creature during each other player's untap step.
{T}: This creature deals 1 damage to any target.
{C}, {T}: Target creature can't attack or block this turn.
{C}{C}, {T}: Draw a card.

Rings of Brighthearth

Whenever you activate an ability, if it isn't a mana ability, you may pay {2}. If you do, copy that ability. You may choose new targets for the copy.

Crystal Vein

{T}: Add {C}.
{T}, Sacrifice this land: Add {C}{C}.

Ultima, Origin of Oblivion

Flying
Whenever Ultima attacks, put a blight counter on target land. For as long as that land has a blight counter on it, it loses all land types and abilities and has "{T}: Add {C}."
Whenever you tap a land for {C}, add an additional {C}.

Zhalfirin Void

When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {C}.

Extinguisher Battleship

When this Spacecraft enters, destroy target noncreature permanent. Then this Spacecraft deals 4 damage to each creature.
Station (Tap another creature you control: Put charge counters equal to its power on this Spacecraft. Station only as a sorcery. It's an artifact creature at 5+.)
5+ | Flying, trample

Liquimetal Torque

{T}: Add {C}.
{T}: Target nonland permanent becomes an artifact in addition to its other types until end of turn.