"Just finished scarlet and I have an question."

I just finished the main story of pokemon scarlet, and this is without doubt the best pokemon game I have ever played, even going beyond BW.However, while I was in the zero zones (not sure if its called that in English, the crater final zone) in order to catch the paradox pokemon, I ended up seeing the second koraidon from afar. I didn't approach him because I was busy catching things, but I'm still curious about this.What I am supposed to do with him ? Is it gonna trigger an fight against him if I approach him ? If so, am I supposed to catch him ? Thanks in advance for any response. via /r/pokemon https://ift.tt/vao2fyW