Oh if it were true to say a wyvern that has taken an arrow to the wing will never attack again. Alas, a wounded dragon will lie low for days until the torn membranes heal anew and it recommences its vengeance. Yet there is a silver lining to every cloud, and a glue concocted from wyvern wings among other ingredients proves to bond easily and reform over time. Such valuable resources are always in short supply, and I would pay you rightly for additional stock.