Unown (D)

Flying.
Elemental Avatar Wizard creatures you control have "{1}, {t}: Tap any number of untapped Elemental Avatar Wizard creatures you control, detain target creature with converted mana cost X or less, where X is the number of Elemental Avatar Wizard creatures tapped this way. (Until your next turn, that permanent can't attack or block and its activated abilities can't be activated.)"
Cyclin