Zapdos’ feather. An item that reduce all electric type moves by 20% damage.
What if we have a similar item to the tc end box, making each 99F more rewarding to run. It could be scaled to a less (around 15%) or higher (around 25%), but I don’t suggest going over 35 because that would be a bit broken. This could boost the reason to run TC (and maybe remove silver key from here), and the fairy could just find somewhere to go.