Vita version- is it possible to save scum?

Just thinking of saving in the portal room, then entering a realm to attempt at making a nether demon and just reloading if it does not work.

It is possible.You need to make a dupe of the save and move it to a spare ram stick or put it into your ps3-4 or anywhere you can move a save 2.Then delete off vita and copy the other save over from the Ram stick or whatever you copied the save onto.