The blisterwood shaft is an item used in River of Blood. It is fletched from blisterwood logs, granting 1 Fletching xp. It can be used on the Sunspear with Wolfbane in the player's inventory to create an enhanced melee sunspear. It can only be crafted during the relevant part of the quest.
In the event of the player having multiple shafts in the inventory, all shafts will be used when crafting the Sunspear. This makes crafting multiple Sunspears impossible.