You'll be worse in melee... that's about the only downside.

I would take a couple combat invocations like agonizing blast to make sure you're pulling your weight in combat but the rest being utility is good.

Ok because people are giving you shit advice. Do not double up on classes, especially don't double up on subclasses. It will make both of you feel like your characters are less unique. You should also make a character that fits the power level of the party. Don't make a bad pc on purpose.