This quest is cooperative. All players in the area of the same faction will have the quest and all updates apply to all players of the same faction.
To start this quest, activate the Ancient Wardstone at the top of the Enkaru Ruins in Mordant Knolls.
Once you have this all the Enkaru will drop the Powered Cells that you need. You can get and charge them one at a time or get all 8 and then go do it. The location of the Power Dock is on the map. Notice that locations for Wardstone quests are marked in a light blue-green instead of yellow.
The tower will HURT you! Run in, click a charger, and get out. The tower shoots laser beams and high explosives.
When the 8th Power Charge overloads and detonates the tower is destroyed and the quest is done. Click on the diamond in the top center of your screen to finish it.