Little Girl – Unhinged common. Little Girl has the smallest unique mana cost in Magic. It's also the answer to a lot of "smallest non-zero" trivia questions.
Wargate – Alara Reborn rare. The image on Wargate shows reality being ripped open and the Maelstrom seeping through. It's a little hard to make out, but that's an Esper Sphinx being summoned to Bant.
Fireball – Beatdown Box Set common. Fireball has had a lot of different wordings as the rules team tried to take the original version and make it work. For the Beatdown Box, it was even printed with a new mana cost: Y!
Cathedral Membrane – New Phyrexia uncommon. Cathedral Membrane shows that Phyrexians don't build things out of wood. And why would you, when you can combine the dark Phyrexian metal with the porcelain-like material that gives the white Phyrexian faction such an attractive aesthetic? It also helps that there isn't any wood on the metallic world of Mirrodin.
Soul Conduit – New Phyrexia rare. From the New Phyrexia FAQ: If a player can't gain life, that player can't exchange life totals with a player with a higher life total. If a player can't lose life, that player can't exchange life totals with a player with a lower life total. In either of these cases, neither player's life total will change.
Exclusion Ritual – New Phyrexia uncommon. From the New Phyrexia FAQ: If the exiled card somehow leaves exile, the last ability will no longer have any effect. In a Commander game, a player may replace Exclusion Ritual exiling his or her commander with putting that commander into the command zone. If this happens, Exclusion Ritual's last ability will have no effect.
Caged Sun – New Phyrexia rare. From the New Phyrexia FAQ: Caged Sun's triggered ability is a mana ability, which means the ability doesn't use the stack and can't be responded to.
Beast Within – New Phyrexia uncommon. From the New Phyrexia FAQ: If the permanent is an illegal target when Beast Within tries to resolve, the spell will be countered and none of its effects will happen. The permanent's controller won't get a Beast token. If the permanent is still a legal target but is not destroyed (perhaps because it regenerated or is indestructible), its controller still gets the Beast token.
Sheoldred, Whispering One – New Phyrexia mythic rare. From the New Phyrexia FAQ: In a Two-Headed Giant game, the last ability will trigger twice at the beginning of the opposing team's upkeep, once for each player on that team. Each player sacrifices only a creature he or she controls.
Slag Fiend – New Phyrexia rare. From the New Phyrexia FAQ: Slag Fiend's power- and toughness-setting ability works in all zones, not just on the battlefield.
Jin-Gitaxias, Core Augur – New Phyrexia mythic rare. From the New Phyrexia FAQ: If a player has more cards in his or her hand than his or her maximum hand size during the cleanup step (after the end step) of that player's turn, that player discards until he or she has that many cards. A player's maximum hand size isn't checked at any time other than his or her own cleanup step.
Fresh Meat – New Phyrexia rare. From the New Phyrexia FAQ: Fresh Meat counts all creatures you owned that went to the graveyard this turn, including creature tokens that entered the battlefield under your control and nontoken creatures you owned but didn't control.
Elesh Norn, Grand Cenobite – New Phyrexia mythic rare. From the New Phyrexia FAQ: If more than one Elesh Norn, Grand Cenobite is on the battlefield, all of their static abilities will briefly apply. Any creatures that have 0 or less toughness and any creatures that now have lethal damage marked on them will be put into graveyards at the same time that the "legend rule" causes the Elesh Norns to be put into graveyards.
Melira, Sylvok Outcast – New Phyrexia rare. Here's a fascinating tidbit from Part 4 of A Planeswalker's Guide to New Phyrexia: Melira is called "the Fleshling" because unlike everyone else on Mirrodin, she was born without any metal anatomy. She is unique in another way: she is immune to the Phyrexian contagion.
Porcelain Legionnaire – New Phyrexia common. The flesh of the Porcelain Legion isn't literally porcelain. It's actually an white, bonelike metal that's inflexible and hard as iron. Under the protective porcelain lie bone, metal endoskeletal structure, raw sinew, and sometimes sensory apparatuses such as eyes or auditory organs.
Xenograft – New Phyrexia rare. Now that Phyrexia has spread across all of Mirrodin, the fighting still isn't over. The Phyrexians have split into five factions which are struggling with each other for control, as highlighted by the flavor text in Xenograft: Jin Gitaxias is expressing a basic philosophical difference with Vorinclex.
Surge Node – New Phyrexia uncommon. The machine priests mentioned in the flavor text of Surge Node are the cenobites, the priests in charge of the inquisition of non-Phyrexian life.
Psychic Barrier – New Phyrexia common. Psychic Barrier depicts a metal mask being ripped apart by psychic lightning. The face is that of a Phyrexian surgeon. This doesn't seem to have affected its mood any, judging by the smile.