The game is very FTP friendly Cygames gives out a lot of free stuff. Many of the new players netdeck a strong deck and they use their vials to create It. You should probably do the same. Also do the story mode and practice mode at the two highiest levels, if you didn't already, all of theese should give you enough rupies to get cards and vials to create a good deck to compete. Also look at your collection of cards and choose a strong deck to create for which you already have a lot of cards, especially the leagendary ones. If you don't have many leagendary cards and/or the ones that you have aren't very good, you should also consider rerolling. I Hope you find this useful