I've always been interested in the more trap-based spellcaster abilities, like the Kobold Sorcerer's Trap Rune ability, or the Rune Domain Cleric's Blast Rune and Spell Rune abilities, and I'm wondering, is it viable to make a spellcaster based around magical rune traps like that? If so, what would be the easiest way to go about it?
Be the villain. Get a lair. Then add traps. Traps everywhere.