Dr. Dreamer
While I'm sure it doesn't matter for him as a cultivator, but pure oxygen is actually toxic at a certain depth underwater (pure oxygen is around 6m or 18ft, you start getting seizures and convulsions). It's why deep divers don't breath even normal air when they go that deep as normal air has the same symptoms at around 200ft or so.
right. I forgot this book was a Chinese knockoff. kept expecting the author's common knowledge to be - well - common. only Chinese education is detrimental to the whole system and kept raising its ugly head in this book. can't handle it anymore. so going to read something else for a while. probably a really long while...đ