Mulligans
General Mulligans
And you might keep Doomsayer against aggresive and Research Project against control opponents, but the main idea is to keep Glyph and card draw over mostly anything.
This is my take on exodia mage, this deck (in my opinion) has became more powerfull overwall with a few minor additions from the Witchwood and Boomsday sets (namely Witchwood Piper and Research Project).
Take it for a spin and tell me what do you think (I might update it in the near future). Additionally Volcanic Potion and Arcane Keysmith are replaceable cards and can be substituted at will so tell me how you differenciated your list 😉