correct me if im wrong but the red thunder has two conditions in order for it to work:
1. martial force/power of the martial god (or the nameless divine arts or smth i cant remember)
2. the thunder god’s power
hence why the thunder god doesn’t have the skill [red thunder]. it was also mentioned in the same chapter that he couldnt have it bc he would need the martial god’s power

Weird, a god of thunder who is supposed to govern all things thunder doesn't have red thunder??