Intruder Alarm

Creatures don't untap during their controllers' untap steps.
Whenever a creature enters, untap all creatures.

Memnite

Springleaf Drum

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

Spirebluff Canal

Spirebluff Canal enters tapped unless you control two or fewer other lands.
{T}: Add {U} or {R}.

Darksteel Relic

Indestructible (Effects that say "destroy" don't destroy this artifact.)

Ornithopter

Twinshot Sniper

Reach
When Twinshot Sniper enters, it deals 2 damage to any target.
Channel — {1}{R}, Discard Twinshot Sniper: It deals 2 damage to any target.

Goblin Welder

{T}: Choose target artifact a player controls and target artifact card in that player's graveyard. If both targets are still legal as this ability resolves, that player simultaneously sacrifices the artifact and returns the artifact card to the battlefield.

Pierce Strider

When Pierce Strider enters, target opponent loses 3 life.

Shivan Reef

{T}: Add {C}.
{T}: Add {U} or {R}. Shivan Reef deals 1 damage to you.

Careful Study

Faithless Looting

Draw two cards, then discard two cards.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Reito Sentinel

Defender
When Reito Sentinel enters, target player mills three cards. (They put the top three cards of their library into their graveyard.)
{3}: Put target card from a graveyard on the bottom of its owner's library.

Virus Beetle

When Virus Beetle enters, each opponent discards a card.

Gamble

Search your library for a card, put that card into your hand, discard a card at random, then shuffle.

Necron Deathmark

Flash
Synaptic Disintegrator — When Necron Deathmark enters, destroy up to one target creature and target player mills three cards.

Combustible Gearhulk

First strike
When Combustible Gearhulk enters, target opponent may have you draw three cards. If the player doesn't, you mill three cards, then Combustible Gearhulk deals damage to that player equal to the total mana value of those cards.

Paradise Mantle

Equipped creature has "{T}: Add one mana of any color."
Equip {1}

Darksteel Citadel

Preordain

Scry 2, then draw a card. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)