These are servants who are unpredictable, crazy, deceitful, or seek to spread chaos.
Atalanta (Alter)
Antonio Salieri
Demon King of the Sixth Heaven
Hades
Set
Loki
Da Ji
Orochi
Genghis Khan
Aleister Crowley
Hisahide Matsunaga
Zhenji
Dalí
Grigori Rasputin