>>31775377If you're chaining for shiny female Salandit, your Sylveon needs to be on the battlefield and alive.
It was recommended before to just have a fainted Sylveon in front to attract a female Salandit, but that only works on the first encounter. When you're chaining, it considers whoever is on the field to be first in the party.
Also, double check if your Sylveon has Cute Charm or its hidden ability, Pixilate.