Grocery store. 4k moon scrolls for 200 revive pots.

Sweeping instances.

P. S. If you can't get 4 wins+ with constance by using at most 40 potions then means or you don't own a power high enough to go for it or that one or two of the teama you bring there are not good enough expendable teams.

i won against a 215k opponent once , well it was pure luck but its true , also can lose against less power players. Im at around 145k. Just saying power not at all. I think the best way is plot instances for potions

one of the important trick is timing. Most high power players often finish matsuri at the start of the event ASAP because they know it easy for them. Therefore, the chance u gonna match up with big opponent are greater if u decide to do it early. i always do matsuri after 9 tails, less trouble easy to win. And if u are on a winning streak, dont hesitate to swap out ur best team and replace them with ur sub team for sacrifice.