"Blast enough mana at something and you can destroy it," he says. "Different combat spells are modulated differently, so some of them have almost no spillover and only hit magically defended things like Devices and mages wearing Barrier Jackets; by default, though, they'll hit undefended stuff a lot harder. A combat spell with enough raw power to flatten this school would knock me back a long way, but it wouldn't damage me much. Physical damage, like, I dunno, big rocks falling on me, accidentally stabbing myself with a fork - it'll damage my form but mostly superficially. It hurts some and it takes mana to repair, but getting crushed by rocks wouldn't be dangerous the way it would be if I took enough magical damage to make it look like I'd been crushed by rocks."