I felt like I was set up to believe this was going be Himari's big power thing even just once but she just served as the MLs "lighthouse". Reviving him felt like Himari wasn't of any use. If he's still going to return to the actual house, and we're teased with him still capable of extinguishing ayakashi (his powers are infinite) then what about Himari? She is still the sole momochi descendant. Doesn't that mean she does have some power to see the house, ayakashi etc.? Ugh. In the end, she's still an outsider, huh Would've been better off without having the Momochi name

I'd rather she figured out a way back after growing in the human realm. Then that meant she had actual character growth even if behind the scenes rather than staying as the "light that reaches far" or wtvr.
TL;DR
FL was just used for ML arc.