embitter (verb)

1. The painting embittered the viewer with its dark and gloomy colors, causing them to feel resentful.

2. In the realm of fantasy, the evil sorcerer embittered the protagonist by casting a curse on their family.

3. The breakup embittered her heart, making her bitter towards love and relationships.

4. In the novel, the protagonist's tragic past embittered him, leading him to seek revenge against those who wronged him.