ROM Hack Question Super Smash Bros Ultimate Event Spirits and CFW

[Gh0sti]

I have been looking high and low for a way to add event spirits such as tetris and resident evil spirits, however I haven't heard a definitive answer nor seen a save editor/tool be able to add them to cfw sxos/atmosphere. Are event spirits similar to how animal crossings does holiday events with a pcap file?

 

[taboo]

Yes, I've heard that Smash Bros uses the same type of file, but I've never been able to find a way to get them like how ACNW's bcat files get shared sometimes.