So I've been tinkering around on herolab and figured I would work on maybe making some NPCs. I can figure out decently enough how to build a LG all the way to a CN character but what escapes me is how to build an effective villain BBEG in a sense. The biggest thing I've seen is that most BBEGs ends up being a spell casting class such as Cleric, wizard, sorcerer, oracle, and witch. I pose the question how do you build your BBEGs? Any good combination of classes that go well together or certain tips to look out for when building an evil guy. Now I did find like one or two tips such as build your BBEG with versatility and defense in mind.
There isn't really a level limit but more of guidelines to follow on what you would do on building a BBEG. For example, PC's are lvl 3-5 and their BBEG is like lvl 7 or so what would be something intriguing that could be built. Would it be feasible to build a raging barbarian, if so would you make him pure barbarian or would mixing him with sorc, oracle, ranger or something. Is it a good idea to build an evil magus or multiclass it into something else. General tips like that.