Nightingale Bow

The Nightingale Bow is a unique archery weapon found in Skyrim. The bow is originally owned by Karliah, but it can be obtained during the Thieves Guild questline. Because the bow is leveled, the magnitude of the enchantments, the base strength and value of the bow are based on character level; meaning that with every level the Dragonborn has advanced when the bow is obtained, the bow does more damage, weighs more, and is worth more.