Sea Devil

He claims on Madame Ching's ship that he is 42.

This cannot be possible.

Apparently, Dan is born in 1976 (according to Sontarans).

Now, for him to be "42" his "current present year" must be 2018. Yet we know, from Eve, that his and Yaz's "current present year" is 2022 (because Dan claims 13 saved the universe "last week" and neither he nor Yaz are surprised at the year being 31/12/2021).

So if he's 42, he's born in 1980.

For 1976 to be right, he has to be 46 now (for 2022 to be his present year) and to include the 4 years he and Yaz lived in the past makes him 50, not 42.

I would personally like to see the return of the Sea devils or the Vashta Nerada in well written stories with interesting A&B plots and a few call backs to previous stories. I don’t hold much hope, but it would be an interesting idea. (Maybe with a new showrunner and better writers though).