mtg signed art cards phyrexia all will be one Series NON-SIGNATURE The Invasion Tree broke through the Blind Eternities and sent Phyrexian perfection coursing across the Multiverse. Art Series: Phyrexia: All Will

The original dual lands are a great example of this

Her +1 ability to return a target land from your graveyard to your hand will allow you to ramp up on mana consistently, especially while running lands like Fabled Passage

If both targets are illegal, the ability won't resolve at all

Marina Vendrell's Grimoire Marina Vendrell's Grimoire has line upon line of powerful text and drawing ability

With Nexus on the battlefield, an Ingenious Infiltrator would trigger the Reaper King when it enters the battlefield, would be indestructible thanks to Knight Exemplar, can be cast from the graveyard by Haakon, Stromgald Scourge, etc

In general, you can add any legal card in a given Magic: The Gathering format