I think that SE is overthinking how to add BLU. As others have said you can have BLU fit with the rules of this game through default monster spells that you would automatically have unlocked from 1-80. And to keep the "hunting" aspect just add a unique UI for BLU that is for spell glamour. For instance you start off with let say goblin punch but in your UI you change the animation to tonberry stab or something similar.

As for the role I could see it as a tank, but I would like to be the opposite of RDM, a Mage mostly in the frontlines with short backline rotation.