I’ll try to explain it from what I know/remember. fmhy.ml and fmhy.tk were backup mirrors of the fmhy wiki, though the UI on both of them wasn’t great. fmhy.pages.dev is the new wiki with a theme by the weeb wiki!
They had those three sites as backup wikis, fmhy.ml got a facelift at some point so that UI is better, whereas fmhy.tk remained the same. Both fmhy.ml and fmhy.tk were taken down around the same time. fmhy.net was bought by the people behind fmhy, page looked like this for a while, then the fmhy.ml wiki was restored on fmhy.net. Now there’s two backup wikis!
pages.dev is a domain owned by cloudflare, it’s used to host the free cloudflare pages - you can’t host a lemmy instance through that domain. fmhy.pages.dev is the newer wiki hosted on cloudflare pages. fmhy.net is owned by the people behind fmhy, they can add sub-domains to point to the Lemmy instance as it’s owned by them as of now.