You know, I liked that Zygarde Aura Break thing we came up with the other time.
How about we come up with something similar with every Legendary? Or a Legendary you like?
A fun, interesting, unique, gimmicky, etc "thing" their ability or some other thing unique to themselves as per their biology or powers or whatever that affects humans or Pokemon negatively or positively maybe related to Aura or maybe related to other thing.