Skill/O

==O' Polar Star, Show the Way==
Rank	User 	Class 	Notes
B 	Calamity Jane	Archer	
==Oath of Protection==
Rank	User 	Class	Notes
B 	Bedivere	Saber	
==Oblivion Correction==
Rank	User 	Class 	Notes
A 	Jeanne d'Arc (Alter)	Avenger	
A 	Angra Mainyu 	Avenger	
B 	Edmond Dantès 	Avenger	
B 	Antonio Salieri 	Avenger	
B 	Hessian Lobo 	Avenger	
C 	Gorgon 	Avenger	
C 	Dioscuri 	Saber 	
==Omen of the Hegemon-King==
Rank	User 	Class	Notes
A 	Alexander	Rider	
==One Cloaked in Death==
Rank	User 	Class 	Notes
A 	Hessian Lobo	Avenger	
==One Night Coat==
Rank	User 	Class 	Notes
B 	Miss Crane	Caster	
==One Who Crosses the Sea of Stars==
Rank	User 	Class 	Notes
A+ 	Zeus (Lostbelt) 	Ancient God, Ruler 	
A 	Poseidon (Lostbelt) 	Lancer, Caster, and Assassin	
- 	Aphrodite (Lostbelt)	Assassin 	
- 	Demeter (Lostbelt) 	Caster 	
==One Who Guides==
Rank	User 	Class 	Notes
A 	Abigail Williams (Swimsuit)	Foreigner	
==One Who Swallows the Land==
Rank	User 	Class 	Notes
EX 	BB (Swimsuit)	MoonCancer	
==One's Own Magic==
Rank	User 	Class 	Notes
B 	Artoria Caster	Caster	
==Oni of Ooe, Riot==
Rank	User 	Class 	Notes
A+ 	Ibaraki-douji	Berserker	Upgrade from Disengage (Fate/Grand Order)
==Oni's Head==
Rank	User 	Class 	Notes
EX 	Shuten-douji	Assassin	Upgrade from Battle Continuation (Fate/Grand Order)
==Oni-kind Demon==
Rank	User 	Class 	Notes
A 	Shuten-douji 	Assassin 	
A 	Ibaraki-douji	Berserker	
B 	Tomoe Gozen 	Archer 	
==Oni-kind Demon (Protection)==
Rank	User 	Class 	Notes
A 	Shuten-douji	Caster	
==Oni-kind Demon (Water)==
Rank	User 	Class 	Notes
B 	Ibaraki-douji (Swimsuit)	Lancer	
==Onmyoudou (Dharma)==
Rank	User 	Class 	Notes
A 	Kiichi Hougen	Assassin	
==Opening the Door of Fantasy==
Rank	User 	Class 	Notes
EX 	Don Quixote	Lancer	
==Oracle of Light==
Rank	User 	Class	Notes
A 	Himiko	Ruler	
==Otherworld Creation==
Rank	User 	Class 	Notes
EX 	Kiara Sessyoin (Swimsuit)	MoonCancer	
==Over the Royal Road==
Rank	User 	Class	Notes
C 	Charlemagne	Saber	
==Overhaul==
Rank	User 	Class	Notes
B 	Leonardo da Vinci	Rider	In Fate/Grand Order Arcade
E 	Leonardo da Vinci	Rider	In Fate/Grand Order
==Overload==
Rank	User 	Class 	Notes
C 	Frankenstein 	Berserker	
D 	Charles Babbage	Caster 	
==Overload Revised==
Rank	User 	Class 	Notes
C 	Mecha Eli-chan 	Alter Ego	
C 	Mecha Eli-chan MkII	Alter Ego	
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