If we wanted to get a tricked out axe to serve as our War Weapon (Which would double as a miscast-mitigater with the grounding rod for the haft), I think the
Lochaber Axe would be a good choice. It would be relatively easy to pivot to from the greatsword we've been using up until now, is distinct from typical Dwarfen axes (But not in a way that makes them a completely alien choice of weapon), and more importantly, is a Great Weapon so we can use it to fight things that are bigger than us easily and use it to ground magic in a pinch.