Overwhelming Surge is a light armor set. When you activate a Class ability, you have a 15% chance to surround yourself with a torrent that deals 1892 Shock Damage to the closest enemy within 12 meters of you every 1 second for 6 seconds.
The Overwhelming Surge set is part of the base game. It drops in Tempest Island in Malabal Tor. Each set item is bound on pickup. You can acquire light armor, weapons and jewelry of this set in the Ancient Elf motif style.