This page seems to be designed specifically for Pyra and Mythra's SSBU appearances, and is linked by the Head and CharHead templates when you type "PyraMythra" and specify SSBU. However, neither this page's title nor its contents imply the characters specifically as Ultimate fighters - it reminds me of the Banjo & Kazooie page, which is a simple disambiguation page and doesn't assume that one is looking for their Ultimate fighter page; after all, these fighters could reappear in another game, and then this setup would be inadequate. What is to be done?
I would personally opt to turn this page into a disambiguation page, again similar to what was done with "Banjo & Kazooie," and create a separate page, entitled something like "Pyra & Mythra (SSBU)," that would take up this page's job of explaining their joint playable appearance (which would be what Head and CharHead link to instead). Sincerely, Samuel the Banjo-Kazooie Boss. 16:36, September 19, 2021 (EDT)