Smoke

Players can't untap more than one creature during their untap steps.

Shatter

Wall of Fire

Defender (This creature can't attack.)
{R}: Wall of Fire gets +1/+0 until end of turn.

Wall of Stone

Disintegrate

Disintegrate deals X damage to any target. If it's a creature, it can't be regenerated this turn, and if it would die this turn, exile it instead.

Mountain

Dwarven Warriors

{T}: Target creature with power 2 or less can't be blocked this turn.

Tunnel

Destroy target Wall. It can't be regenerated.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Fire Elemental

Bird Maiden

Urza's Chalice

Whenever a player casts an artifact spell, you may pay {1}. If you do, you gain 1 life.

Fork

Copy target instant or sorcery spell, except that the copy is red. You may choose new targets for the copy.

Manabarbs

Whenever a player taps a land for mana, Manabarbs deals 1 damage to that player.

Urza's Mine

{T}: Add {C}. If you control an Urza's Power-Plant and an Urza's Tower, add {C}{C} instead.

Magnetic Mountain

Blue creatures don't untap during their controllers' untap steps.
At the beginning of each player's upkeep, that player may choose any number of tapped blue creatures they control and pay {4} for each creature chosen this way. If the player does, untap those creatures.

Yotian Soldier

Burrowing

Enchant creature
Enchanted creature has mountainwalk. (It can't be blocked as long as defending player controls a Mountain.)

Urza's Power Plant

{T}: Add {C}. If you control an Urza's Mine and an Urza's Tower, add {C}{C} instead.

Glasses of Urza

Sol Ring

Mox Ruby

Urza's Tower

{T}: Add {C}. If you control an Urza's Mine and an Urza's Power-Plant, add {C}{C}{C} instead.

Wall of Spears

Defender (This creature can't attack.)
First strike

Urza's Avenger

{0}: Urza's Avenger gets -1/-1 and gains your choice of banding, flying, first strike, or trample until end of turn. (Any creatures with banding, and up to one without, can attack in a band. Bands are blocked as a group. If any creatures with banding you control are blocking or being blocked by a creature, you divide that creature's combat damage, not its controller, among any of the creatures it's being blocked by or is blocking.)