mannerism, habit, vice, trait, fault, kink
癖 centers on a persistent, often unconscious personal tendency: a mannerism, habit, or trait that can be a minor fault, vice, or even a quirky kink.
癖 combines 疒 (sickness) with 辟, which likely contributes the sound and the idea of something bent or deviant, suggesting a pathological or ingrained habit.
The sickness enclosure 疒 wraps around 辟, like a chronic condition. Picture a person whose mannerisms are so ingrained they seem like an illness.
For ヘキ, imagine a person with a strange habit of always saying 'hecky' instead of 'heck': hecky -> ヘキ, and their mannerism is a quirky fault.
habit (usu. a bad one); tendency
disposition; inclination; characteristic; idiosyncrasy; propensity
pet saying; favorite phrase; stock phrase; catchphrase
fastidiousness; love of cleanliness
fault
bad habit; vice
drinking habits; drunken behavior; drunken behaviour
kinky hair; frizzy hair; unruly hair; curly hair
having sticky fingers; compulsive thievery
bed hair; hair disarranged during sleep
trait; peculiarity; idiosyncrasy
addiction
philandering; itch for women
vagrant habits; vagabondism; wanderlust
and yet; even so; nonetheless; for all that
habit of putting things off; truancy habit
abruptly dissolving relationships (as if pressing the reset button in a game)
to be hard to deal with; to be an eccentric; to be idiosyncratic
some habits; some eccentricities
eccentricity; crankiness