This is usually the upgrade that people go for the least (the earring) and it’s a shame because it’s very cool and interesting from a design viewpoint. The main reason people don’t use it is because the wing boots and the tether help with slade’s very poor recovery, making them somewhat of a necessity.
The earring I feel could help with that too, as having it bounce somewhat high up when used on an opponent or when close to a wall would help it see use and viability.
Alternatively, give the move a bigger disjoint to make it seem worth it to use against opponents like zetter and kragg going for juggles
Similar to greninja’s down air

I would buy it more if when you did the dair+shield input, it behaved like adult Link in smash 4/ultimate, along with melee going link. The spike hitbox is above Slades head for the normal dair like young link, but I always wished the spike hitbox was below like adult link