In relation to my review, I gave this character a try and... have a few ideas of how he could play better.
Starting with the elephant in the room,
vanilla dash mode is doing him no favors. Perhaps letting him keep it in the air regardless of speed or while he's climbing walls (or both) would help it flow a bit better (aerial preservation would also allow him to keep it a bit more reasonably while gliding.) The fact that he also can't break spikes with it (while he can certainly
damage enemies and bosses) feels odd.
Second thing: his spindash. Again, the aimed spindash idea is rather interesting, but the spindash itself is too strong and has little to no variance in it's strength (which makes it feel like a thok bound to the ground.) I would try letting the spindash be a little stronger than average while it's uncharged, but have the aiming stuff show up after you charge it a bit and
let it get really strong. I also think making it operate like a normal spamdash (press the button to
spindash again) is overall not the best idea, but I don't doubt it could be tweaked to work with his kit a bit better.
Then there's some small stuff that I think could help, starting with tweaking his recurl. Letting him recurl from stuff like pain, spring, and falling states isn't too bad of an idea, but specifically recurling from glide feels a bit... off. I think letting the player glide again after hitting something would make it really fun to utilize and flow a bit better with how he plays.
After that, I'd recommend maybe giving him a passive of some sort stemming from him being a powered up version of Knuckles (for example breaking spikes upon contact as if they're bustable walls) along with changing the effects for some actions (spindash, dash mode, and having a nuke shield all using the
exact same rainbow effect makes it super hard to tell when I have dash mode sometimes.)
Lastly, the ability to just...
have an armageddon shield from pressing custom 3 really feels haphazardly attached and I'd say it has no real reason to be here. If you
really wanted to give him a ring based ability though, maybe make it so you get a different shield depending on how many rings you have when you press custom 3?
Overall I'd say CK here has quite a bit of potential to be really fun and quite interesting to play, but in his current state I'd say he could definitely do with some changes.