Harem
Akeno Himejima
Rias Gremory
Sona Sitri
Tsubaki Shinra
Murayama
Katase
Momo Hanaki
Reya Kusaka
Tomoe Meguri
Tsubasa Yura
Xenovia Quarta
Irina Shidou
Rossweisse
Koneko Toujou
Kuroka Toujou
Grafiya
Serafall Leviathan
Ravel Phenex
Jeanne
Ingvild
Yakasa
Mittelt
Kalawarna
Raynare
Jeanne D'Arc
Jeanne D'Arc Alter
Artoria Pendragon (Lancer)
Artoria Pendragon Alter (Lancer)
Ishtar
Ereshkigal
Scathach
Skadi (Maybe not sure)
No multiverse travel, just some change in plot to introduce some Fate characters.
Sheesh Too many
Well I won't butcher any character and it won't be a dumba** harem so don't fear.
Leaving it aside comment if you want to add and post their images as well at their name.
Peace
PERTIMBANGAN PENCIPTA 
ZephyrusOfWind
ZephyrusOfWind Leave Power Stones
Status Power Mingguan
-- Peringkat
Power 
-- Power
stone