New Phantom Type to Balance Elytras

Everyone's heard how overpowered elytras are, so my idea doesn't change anything about the elytras, but instead... the Flying.

New phantom type, called the Spirit- it's hard to come up with names- spawns during the day and only when the player is above y level 160 or some average cruising altitude- experimentation needed.

It'd act almost like an hostile flying dolphin, where it circles above you until you start flying, at which point it'd dive down like a normal phantom, but unlike a phantom it would try keep up with you in the air, and it wouldn't back off much when you get hit.
hitting for 3.5 hearts without armor on easy/normal and 4 on hard, while having 30 hit points, potentially also having an actually implemented scale mechanic, where the longer you spend at a high altitude (and the higher you go), the larger the Spirits that spawn

The only way to shake it off (besides killing it) would be to land or fly close enough to sea level (like, y100-ish), you could also fly at night time but then you could run into normal phantoms (which could also attack flying players more).

It would look like a longer phantom (better at staying with a player who's flying), but be greenish gray on top and Bright sky blue on the bottom (maybe taking on the sky color of the biome you're in), to try camouflage.

I think this would make players rethink their travel strategies, do they fly and risk getting attacked by Spirits? glide closer to the ground? or do they take a grounded method instead?