Hot take: Lu Guang's fevers
What if Lu Guang is actually constantly in pain because of the overload of memories and information of all the timelines he has to keep in his brain but endures it anyway.
We all know he perfectly remembers what should happen every day, at every hour and at every minute (yes he wrote it down somewhere but he can't check it every single time, so probably he memorized it).
And I'm not talking about physical pain, but more like strong headaches, and when something triggers his ptsd about the first timeline, he instantly gets a fever (like in the Bridon arc after they "first met" Vein and in s3 when he finds out Xia Fei went missing). Like, he literally FAINTED TWICE and had 40°C (104°F) fever the first time!
Idk if that's normal??