Honestly, I doubt there will be a new Deathscyther. Given that D and D2 were too OP for various reasons and had to be banned, thus causing the release of the notoriously meh kD to nerf the line, I really don't see them taking another shot at it. Besides, if we do have a bey named Dead Hades coming as has long been presumed from the copyright bot, another Death-themed bey would probably be overkill.
What I do want to see, roughly in order, is:
Trident: The original Trident was notoriously bad and easy to burst, but Screw Trident's rubber bumper gimmick was both incredibly unique and on the cusp of usability, even succeeding in winning a tournament as a surprise part just after release in its RLC. A Super-Z bey with the same rubber bumper gimmick might just make this unique idea work more smoothly, especially given how much Screw Trident was underappreciated.
Chaos: Chaos and Deep Chaos are two of my favorite layers, and Deep Chaos' flexible "bound defense" gimmick and sloped edges made it both unique and powerful. A Super-Z Chaos with flexible edges and metal could prove to be immensely powerful, and I just really want to see this awesome looking line stay relevant.
Unicorn: You can probably figure out at least one reason from my name alone, can't you? Unicorn and Unlock Unicorn were simply beautiful layers, if underpowered, perfectly capturing a wild unicorn rearing for a fight. Now imagine if Unlock Unicorn had metal in the horn, lined with plastic, alongside metal strewn about the remained of the edge. There's just so many ways to make a beautiful upgrade to U2 with the added metal, and I'm just really hoping it comes to pass.
Anubis: Probably a bit understated as well, Acid Anubis was a layer I really just wanted to work out better than it did, alongside Yell. We've lost the whole Egyptian theme without this line and the Horusood line, neither which got God versions, and I think between the two this would make a nicer-looking and more functional layer.
Zeus: Zeus' design has always been unique with its metal ball gimmick, and has always been a notable presence in the Anime. Perhaps it's time for it to return, and this time with even more balls! Instead of just having one channel, a layer with multiple channels with balls in them spread across the layer might make the gimmick relevant enough even with Super-Z weights, and Planet is well due for an upgrade to try and iron out its flaws too.
Cincinnati-based Organizer, and owner of every single currently released TT Burst bey part in at least one color. Hard to think of anything I don't have from MFB either...