This is a pure filler episode, there isn't any plot progression nor any new spirit appearance. This episode isn't in the LN as such it is an anime only. You're looking for some fan service in this episode? Too bad there isn't that much and as you have observed in the previous episode, the studio doesn't show any nipples in their characters and even in the uncensored version. If you are a completionist then go watch and if you want to proceed with the plot then skip 😉