Perfect thats what i do in bgs. I lay down magma and fire nova and it keeps any stealth from coming to me. They wont attack if they cant get element of surprise. But also even tho hes stealth when they get to close you can still hear him. Just turn up ur abience and pay attention for the woosh sound. Youll know hes in the area then drop fire nova and if hes that close it will pull him out.