Konami finally hit box SR, I wouldn't be surprised if in the future, a box UR also gets hit.
Considering how dominating it can be as long as DARK "HERO" monsters exist, I can see Konami just go straight to the core of the problem, and limited Anki.
(Mask Change is less likely, because Anki is not the only Masked Hero in the game)
If they limited Anki, then I can see the next Structure Deck for Judai to be themed around the less powerful Masked Heroes, to act as some sort of replacement.
A large part of why Anki is so powerful is because most of the good HEROes are DARK. Elemental HEROes for the most part are not very good on their own. (At least the ones acceptable here.) I don't think even Koga's going to make the deck viable when you need to run cards like Neos Alius to make it work.
Since I only have two anki, I guess I want both Mask and Trunade at semi ban list. Either use your two masks and face the opponent's backrow, or have two trunades but cannot play anki at all. XD