The wilderness sword 4 is a reward from completing the elite Wilderness tasks given to you by Kolodion in the Mage Arena. It has stats similar to the Superior dragon longsword, Blisterwood sickle, and abyssal whip. If lost or destroyed, it can be reclaimed from Kolodion or Mr Ex for 100,000 coins. Dying in PvP drops 20,000 coins for the killer.
The Wilderness sword 4 can be augmented by using an augmentor on it.