Daily Yo-kai Watch Factsさんのイラストまとめ

6 Deva Yo-kai were added in Yo-kai Watch Blasters 2, those being Yami Enma, Fudoumyouou, and the 4 previous Lord Enmas.

Steve Jaws' toy medal received a voice change after the Japanese DX Yo-kai Watch Model Zero in the DX Yo-kai Watch Model U and onward for seemingly no reason.
Model Zero audio clip (0:11) : https://t.co/nkdVnQbtG6
Model U audio clip (0:36) : https://t.co/cCZ5EMbQw7

Bronzlow is the main villain of the Yo-kai Watch Shadowside manga. His presence solves many plotholes in the original Shadowside series, for example explaining how the Yo-kai lost their memory and how their physical forms changed over the 30 years.

Jabow is a snake Yo-kai from Yo-kai Watch 4. He's actually the mascot of Omuta city in Japan's Fukuoka prefecture and was designed by Level 5!

In the game Yo-kai Gakuen Y Wai Wai Gakuen Seikatsu, Chiaki Hebiyama is confirmed to be a reincarnation of a Yo-kai. However he is the only one whose Yo-kai from their previous life is unknown and he is speculated to either be the reincarnation of Venoct or City Licker.

Gabby's Japanese name could be a reference to Princess Peach from the Super Mario series, being that her name is "Speech-hime" and Peach's Japanese name being "Peach-hime".

After Shien's death in M05, Shien was split into a good half and a bad half. The good half became Lord Enma. Yo-kai Watch 4 implies that the bad half is Lucas. Shien's ++ Blasters mission is even called "Hi no kage ni nemurishi maou". Lucas' name in Japanese is "Hikage Mao".