Ethereum

Overview
Ethereum is a common level 55 longsword, purchased for 15,000 Vel in Helmfirth. It has 12% crit and 524 damage. At max damage (10+), it deals 733 damage which currently makes it the second strongest Longsword behind Sand Aerosol at +20 which deals 838 damage (however it is far less time consuming and cheaper to acquire Ethereum.)