Hints:
Per the central entry, first locate a synonym for a certain across entry. That special entry is appropriately clued. Don't forget to think about the clue for that entry when you are looking for a synonym.
The certain across entry is the last across. If you look at that clue, a more common answer (the synonym) should come to mind. If you know your mythology, it's the Roman counterpart.
Hopefully by now you have a 5-letter synonym. You can Google that word and “dance” to get a two-word answer. The long entries show the “remix”.