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