A fun character I used on my first playthrough was a multiclassed tempest cleric / storm sorcerer. Level order was sorcerer 1 -> cleric 2 -> sorcerer 10. Starting stats were 8/14/15/8/12/17, increased to 8/14/16/8/12/20 during leveling.
The gear I used was balanced between survivability and spell power. (Medium armour, adamantium shield, some items to increase my spell save dc and spell attack bonus)
My "signature move" was combining destrucitve wrath with sorcerer spells. Good picks for that are twinned chromatic orb and at higher levels lightning bolt.
A quickened create water (before you cast your main spell) applies the wet condition to targets, making them vulnerable to lightning (and cold) damage, doubling the damage they take.
The short flight from tempestous magic allowed me to easiely reposition in melee range when needed or to use the terrain to have the high ground.
