Well he can. Tossing fireballs, an ice shard, lashing out with a wind blade, and other things are within his capabilities. He's not particularly skilled at such things since he found one thing he wanted to do with Prima, and practiced specifically towards it, but he can if someone sat him down and said, "Prove to me you're actually a competent mage and not some one-trick pony."
If they wanted a firestorm or blizzard, they'd have to go find Runik instead.
If they wanted a firestorm or blizzard, they'd have to go find Runik instead.