
Does anyone know if there's a raw novel of this anywhere?

I couldn't find a English translation but you can MTL the novel here https://booktoki468.com/novel/7891100?stx=여백의+흔적

How can a npc become sentient tho... is bro AI generated??

He became sentient because Doha and Seongchan made Bada insert a tape (aka make a game save)
I hope this helps! (I still have to add info from season 2 tho)
https://docs.google.com/document/d/1fyfND0KcEKCLjX-4X9l66b9U6diWfaakpy1NOWcA8mY/edit?usp=sharing
Why does the art look so familiar...