Putting my extreme distaste for UB aside for a moment, kind of cool that they're doing more with Planes/Phenomenons. Exterminate also seems like it could be pretty strong, particularly with Changeling.
Alt art frame with the Humanist sans-serif font is pretty wild for an MTG card.
The cards themselves look like really neat designs (fun to see Suspend return! I'm guessing Time Travel works with it?) but even as a casual fan of Dr. Who it just feels really weird to see it in a game of Magic. I'll probably just wait for the UW versions like I did with the Stranger Things/Street Fighter/Walking Dead cards
According to the reminder text on one of the cards, time travel seems to be like proliferate for suspend counters, except you can either add or subtract from any suspended cards. Could be fun if all doctors are messing with when things happen in different ways. I can feel the timely-wimey shenanigans from here.
And I thought we were done with new cards for a bit. Well, they do look fairly cool. Chances are they'll put a lot of effort in and the decks will turn out to be very good, just hopefully they're not being sold for $80 again.