Do you have any friends that play mc? If not, ask other Youtuber.
The idea I did before but found it too much to keep up with since we got 4 mc series at that moment.
Download the map Skylia island, put it in the server and make teams, 2 of 2 players 3 of 2 or whatever you like.
Make sure the server is vanilla and fight eachother to death, offcourse after a few episodes of minimg building and s**t.
Make sure you upload it when someone has lost, otherwise the oppenents can see your base

I hope you like the idea, if not I gave someone elese an idea or a concept to creativicly work with.