What is the ruling on one who follows fashion in their hairstyle (spiky hair)?

It is permissible to style hair in any way for adornment or to ease its burden, provided that it does not involve imitating disbelievers or transgressors, or men imitating women, or vice versa. If it does, then it is impermissible, due to the Prophet's (peace be upon him) saying: "The Messenger of Allah (peace be upon him) cursed men who imitate women and women who imitate men," and his saying: "Whoever imitates a people is one of them." Imitating disbelievers is only in matters specific to them. If following fashion trends in hair styling leads to imitating disbelievers in what is specific to them, then it is impermissible; otherwise, there is no objection.