most intractable

awkward bullheaded cantankerous contrary hang tough hard-line headstrong immovable incompliant incurable indocile indomitable insoluble locked in mulish obdurate obstinate pat pertinacious perverse pigheaded recalcitrant refractory resolute self-willed set in stone tenacious tough tough-nut unbending uncompromising uncooperative undisciplined ungovernable unmanageable unpliable unruly unyielding wayward wild willful

amenable easy facile manageable

incurable intransigent stubborn uncompromising unmanageable

awkward bull-headed cantankerous contrary fractious hang tough hard-line headstrong immovable incompliant indocile indomitable insoluble locked locked in mulish obdurate obstinate pat pertinacious perverse pig-headed recalcitrant refractory resolute self-willed tenacious tough tough nut unbending uncooperative undisciplined ungovernable unpliable unruly unyielding wayward wild willful

willing

manageable