Sure, here's an example of unique content optimized for the keyword 'frisk x chara' using synonyms:
1. The protagonist x Chara
2. The player character and the lost soul
3. The explorer and 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.