First u need 2 b in Mephistos realm and u need
Touch of Death:Press Left, Right, Down, Down, Right, Left, Start during game play.
and in the area where u throw the demons in the Lava go 2 where they pop up and keep pushing X or O and u will level up extremly fast trust me me and my nephew did this 4 awhile and in minutes we went from level 33 2 level 69

the only reason we stopped is 2 finish the level