Inexorable

In*ex"o*ra*ble (?), a. [L. inexorabilis: cf. F. inexorable. See In- not, and Exorable, Adore.] Not to be persuaded or moved by entreaty or prayer; firm; determined; unyielding; unchangeable; inflexible; relentless; as, an inexorable prince or tyrant; an inexorable judge. "Inexorable equality of laws." Gibbon. "Death's inexorable doom." Dryden.

You are more inhuman, more inexorable,
O, ten times more than tigers of Hyrcania.
Shak.