ruffianly

desperate fierce hard hard-nosed harsh narrow resolute severe stern stiff strict terrible

adamant firm refractory savage

arbitrary callous confirmed cruel drastic exacting ferocious fixed hard-bitten hard-boiled hard-line hard-shelled headstrong immutable inflexible intractable merciless obdurate pugnacious ruthless stubborn taut unalterable unbending uncompromising uncontrollable unforgiving unmanageable unyielding vicious violent

amenable easy flexible pliable pliant tolerant uncertain yielding

controllable delicate fragile tender