what happens when i attack a flying card magic the gathering

[kiokitu]

what happens when i attack a flying card

[Arix]

DISQUALIFIED FOR SAVAGE CHEATERY

You never attack creatures.

[DatAsh]

Yu-Gi-Oh, this is not. Thou shouldst read the game rules.

[kiokitu]

then what do i do if I wanna kill that creature but my friend never attacks with it and it only blocks creatures which are weaker

[DatAsh]

Cast a removal spell. Cards like Murder, Searing Spear and now Rapid Hybridization (functional reprint of Pongify). Creatures are used to attack players, and the defending player may block. Those are the rules of the game.