Have you explored the Wizard City Underground yet? Take a look at the detailed quest line you will need to go through so you'll know what to expect including all the main line cheating bosses leading to the Devourer!
In this Neumian Lion guide you can find this boss' cheats as well as some suggestions on which spells to put in your deck. This boss is gorgeous, but how can you get past its incessant cheats? Find out here!