This is a Wild Area event held by Sword and Shield.
This event allows Urshifu to spawn as event boss in 5-star raids, though important to note that it cannot be caught.
Index 106 also mistakenly features the shiny Urshifu. Index 107 was updated to solve the error.
Defeating Urshifu gives the player rare items not usually available in raids, such as Max Mushrooms, Max Honey, Apricorns, Choice Band.
To import these files into your save, use PKHeX's block importing function. Our tutorial should guide you through it.
Our first post of this page would contain some data relevant to the importing stage.
There's info and some common questions regarding Wild Area Events here.
To see other Wild Area Events, here.