The character is so poorly designed and universally hated something needs to change. No, I don’t think giving a character lagless aerials and 0 IQ flowchart auto-combos because he’s “slow” in the air is good or interesting game design at all. I think the best way to go about doing it is to gut all of the cheesey aerials and smash attacks and really lean into his poison, bubble and tongue gimmicks. As it is now those things are entirely optional, you can just spam tilts, grabs, nairs and bairs and be fine without them.
Sadly the “lagless aerials and 0 IQ flowchart auto-combos” applies to more than just Ranno. Instead of just Ranno, endlag and landing lag needs reworking across most of the cast.

everyone of his aerial hitboxes needs to be nerfed a ton as well. This character is the opposite of precision.