John's adversary in the debate was a renowned theologian.

He faced a formidable adversary in the chess tournament.

The adversarialness of the debate made it difficult to find common ground.

He played the game adversarially, trying to defeat his opponent at all costs.

The adversaries plotted against each other in a game of wits.

He had an adversarious attitude towards his competitors.

Her adversariness made it difficult to work with her.

The adversariality between the two political parties is evident in their constant disagreements.

He has an adversarial attitude towards authority.

Adversarial systems are commonly used in legal proceedings.