Gatecrash

Horror of the Dim | Creature | Horror | {U}: Horror of the Dim gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.) | Jack Wang

Mortus Strider | Creature | Skeleton | When Mortus Strider dies, return it to its owner's hand. | Tomasz Jedruszek

Paranoid Delusions | Sorcery | | Target player mills three cards. Cipher (Then you may exile this spell card encoded on a creature you control. Whenever that creature deals combat damage to a player, its controller may cast a copy of the encoded card without paying its mana cost.) | Christopher Moeller

Psychic Strike | Instant | | Counter target spell. Its controller mills two cards. | Mathias Kollros

Deathcult Rogue | Creature | Human Rogue | Deathcult Rogue can't be blocked except by Rogues. | David Palumbo

Dimir Guildgate | Land | Gate | Dimir Guildgate enters the battlefield tapped. {T}: Add {U} or {B}. | Cliff Childs