obdurate

stubborn/unyielding hardened against good influeces

Synonyms

inflexible

unshakable

unrelenting

Antonyms

flexible

fluid

submissive

Sentences

1. The outdated, obdurate teacher refused to let go of her tradition of using chalk boards.

2. Often times stories involve a heroic protagonist and an obdurate enemy who the hero eventually overcomes.

The Mr. Men Show - Mr. Rude Vs. Mr. Stubborn