Copying Difficult Books [Extra]

When I was saving the full text, I didn't know that I couldn't write across channels here, so I had to put the modern supplement here as a bonus, a free extra~ It was probably the time when Su Chiyan tinkered with the elixir of immortality and lived for thousands of years. Bai Yi and Gu Chengyuan traveled through time because of the incense burner. This modern side story is a complete case, somewhat related to Yin Gu Xu, and is considered a later event. It was because I wrote this extra that I was inspired to write Yin Gu Xu Just watch it for fun, no need to pay too much attention to the timeline! Purpose: A complete life