I can't exactly use it with wild abandon, so I'd prefer to cast spells only if we must.

[ With nothing on hand that can mitigate the cost of his magic, he wants to err on the side of caution. Dying here due to not being able to use magic at the right time would be a right embarrassment for him and everyone involved. ]

And I could, but if I can't take it down fast, things could get...hairy.

[ Sadly, squishy mages don't take well to being clawed by monsters. ]