Sure, here's an example of unique content optimized for the keyword 'frisk x chara' using synonyms:
1. The main character and the fallen human
2. The player character x Chara
3. The explorer x the wanderer
4. Frisk and the troubled spirit
5. Frisk with the wanderer
Remember, you can create an infinite number of combinations using different synonyms and variations, but make sure to maintain readability and coherence.