placable

unbending, unyielding, steely, unswerving, pitiless, indomitable, obstinate, unrelenting, adamantine, uncompromising, ruthless, remorseless, indefatigable, relentless, imperturbable, inscrutable, unregenerate, mulish, maniacal, machinelike, fearsome, unblinking, steadfast, unshakeable, stolid, inexorable, unreasoning, monomaniacal, unappeasable, unconquerable, unwavering, intransigent, obdurate, stoical, saturnine, cunning, unflappable, vengeful, untempered, stoic, imperious, merciless, incommunicable, unmerciful, ferocious, unseeing, insistent, depthless, amoral, unflinching, impassive, untamable, resolute, irrepressible, monkish, unbendable, unshakable, murderous, antipathetic, insolent, changeless, pertinacious, grand inquisitor, uncomprehending, visaged, phlegmatic, tyrannical, brutish, emotionless, atavistic, domineering, unerring, staunch, coldhearted, redoubtable, unremitting, hardbitten, somnambulistic, sphinxlike, rapacious, protean, ineluctable, immutable, palsied, stubborn, unashamed, unquestioning, idee fixe, sociopathic, mephistophelian, malevolent, perfervid, doughty, baleful, oedipal complex, easeful, unfeeling, ardent, vivifying, beatific, irascible, tenebrous, bears, descend, die, motionless, trophy, 1s, \u2022, admits, affirm, agitations, alarms, alien, allurement, alter, appears, associate, athena, backwards, bas, be, vindictive, revengeful, stern, unforgiving, unpitying, baffled, fierce, embittered, rancorous, immitigable, sullen

grimly

grim, unmitigable