I'm not 100% clear on how upgrades will be handled with vaults. For example, if we had 3 novas in our vault, do we have access to supernova? My understanding would be with that example of 3 novas, we could make a deck with 3 novas, 2 novas 1 supernova, 2 supernovas 1 nova, or 3 supernovas. Is this correct? If not, how does it work?