inexorable

Impossible to stop, alter, or resist; inevitable.

Not capable of being persuaded by entreaty; relentless.

Not to be persuaded or moved by entreaty or prayer; unyielding; unrelenting.

Synonyms Inexorable, Unrelenting, Relentless, Implacable; immovable. Inexorable, literally not to be moved or changed by prayer or petition, expresses an immovable firmness in refusing to do what one is entreated to do, whether that be good or bad; it is also used figuratively.

Not to be persuaded or moved by entreaty or prayer; firm; determined; unyielding; unchangeable; inflexible; relentless; -- of people and impersonal forces.