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