othinus
A Magic God that was based on Norse mythology Odin. Magic God are the purest, most perfect Magician that encompasses every possibility, including positive and negative (thus all her magic always has 50/50 chance of succeeding). She wield Gungnir to cover her 50/50 weakness, and to remake the world.
At the end of her arc, she uses "Turn to Fairy" spell to undo her status as a Magic God and killing her. But due to Kamijou Touma's Imagine Breaker interrupting the magic, she survived the spell and turned into 15cm fairy who lost all of her magic.