Spell Rupture 
Instant
Counter target spell unless its controller pays 
, where X is the greatest power among creatures you control.
Legality
standardNOT LEGALpioneerLEGALmodernLEGALlegacyLEGALvintageLEGALcommanderLEGAL
Instant
Counter target spell unless its controller pays , where X is the greatest power among creatures you control.