Stories of the Japanese 01334 [Muromachi/Yoshimochi Period] Strange Incidents Befalling Emperor Shoko

As I have mentioned before, Emperor Shoko fell into critical condition several times during his life, and the causes recorded for these incidents are quite bizarre.
First, when Emperor Shoko caught a bad cold in October of the 25th year of Oei (1418), the cause was said to be:
"He encountered a monster without a lower body in the latrine, and his health deteriorated after the monster spoke to him."
I thought this might be some kind of delusion, but it turns out that Shirakawa Sukemasa (1895–1419) also saw the same monster, so it may not have been a simple delusion. Incidentally, Shirakawa Sukemasa died of illness about half a year later at the young age of 25.
Next, when Emperor Shoko fell into critical condition in July of the 32nd year of Oei (1425), two strange events were recorded.
One was:
"A monster-like nun appeared and then vanished,"
a story similar to the previous one. The other was:
"A turtle appeared and bit the Emperor, so the Emperor climbed onto its shell and wrestled with it. After the struggle, the Emperor fainted and fell into a critical state."
Both of these were recorded as rumors in the diary of Prince Fushimi-no-miya Sadafusa. While they are hard to believe, they seem to have been rumors that were spoken of quite seriously at the time. Could this be a curse from Emperor Go-Kameyama, the last emperor of the Southern Court?
Then, in January of the 34th year of Oei (1427), an incident of a different nature occurred. When a court lady entered the breakfast room, she heard a human voice coming from inside the Seiryoden, which should have been empty. Suspicious, the lady opened the sliding door, but no one was there.
The lady then peeked inside the kichō. A kichō is a partition made of thin silk.
The lady was astonished when she lifted the kichō. A man with his hair tied in a topknot was lying there asleep. The man was immediately taken into custody.
When they investigated the man's background, it was discovered that he was the nephew of the famous painter Tosa Yukihiro. According to Tosa Yukihiro, this nephew had become insane due to illness. The man had been entrusted to Yukihiro, but allowing him to infiltrate the Seiryoden became a major scandal within the palace.
What were the strange incidents that Emperor Shoko frequently encountered, especially the monster without a lower body and the giant turtle? Was Tosa Yukihiro's nephew truly just wandering into the Seiryoden? The truth is unknown, but in any case, it cannot be denied that these strange events may have disturbed the Emperor's mind and shortened his life.