This build works starting as either a Pyromancer or a Bandit however starting as a Pyromancer gains you one extra attunement slot for a spell of your choice.
Use Great Magic Weapon at the start of a match to inflict extremely high damage with the Demon's Greataxe.
Armour was chosen for decent poise and good Physical Defense while still having a fast roll many more options become available should you make the sacrifice of using Medium rolls.
