Pair
Card pairs, in Magic: The Gathering, are any two cards that are more often than not featured in the same set and share a number of characteristics, such as card names, mana costs, rarities, card types (and, if applicable, creature subtypes and powers/toughnesses), and abilities or effects. Pairs of cards may be mirrored pairs or matched pairs.
Matched pairs
A matched pair (or parallel pair) is a pair of cards that are of the same color and the abilities refer to another enemy color (or an allied color or another allied color).[1] Examples of matched pairs include Disciple of Grace and Disciple of Law and Aven Smokeweaver and Treetop Sentinel.
Mirrored pairs
A mirrored pair is a pair of cards that are of different colors, often being of enemy colors and featuring color-based abilities that are inverted in the other card of the mirrored pairing.[2][3] Examples of mirrored pairs include White Knight and Black Knight, which is amongst the most iconic mirrored pairs in Magic;[4] Holy Strength and Unholy Strength; Blue Elemental Blast and Red Elemental Blast; and timeshifted cards of Planar Chaos and the original cards to which they pay homage.