Is Katana Master's buff in combat intended to be removable by purging effects like Requinite and Null Shell?
Currently it is able to be removed, which seems unintentional given the requirements to have it work in the first place.
I'm hoping it wasn't intentional, personally.
It shouldn't be, it has the right tag for it. Does it dispell any food status?
Food statuses can't be dispelled last I checked, unless something changed recently they've never been able to be purged by status wipers like Wash Away and Null Shell.
But just to be sure I tried using Null Shell and after three attempts it didn't remove the food status the victim had. It could possibly be an issue with Requinite if it makes a different check than Null Shell for what statuses are valid to wipe, but I only tested using Null Shell assuming the effect would be the same.
I'd double check your testing and what you're using to dispell it, along with if food statuses can be removed the same way.