The fate of a hero (Nasuverse/Percy Jackson crossover)

while looking I realized two things. There's not many fanfic featuring nasuverse Karna, and there's not many fanfic involving a fate crossover. I've decided to make this both.
Note: Karna will be heavily nerfed as even his nasuverse version could probably one shot kill almost any Percy Jackson demigod. Also, apologies if I get character personalities or lore wrong, I only recently got back into the Percy Jackson books. If you see mistakes feel free to correct me

Karna is confused, he woke up one day almost certain he had never existed before. Not too far from the truth. He in fact did not exist in this world before. In the last grail war he was a part of his master was a little odd and used their wish to send him through the worlds. He flew through timelines and eventually landed here, in a place where divine spirits still hold some of their power, where the age of humans has not yet destroyed them all. Now he must survive in an unfamiliar world and with no memories except his name, Karna

Disclaimer: none of these characters are my own, same goes for any images. I would love to use my own but i cannot draw decently to save my life