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Enna Core Upgrade Kit (엔나 코어, Enna Ko-eo Eobgeuleideu Kiteu) is a very rare special item that are used to upgrade normal Lighthouse. By upgrading the Lighthouse with this item, Light Bearers can utilize a special skill called Enna Core.
On a purely theoretical level, it is an extremely difficult to divide one side of a Lighthouse since it will causes a massive overload and overheat. As such, normal Lighthouses cannot utilize Enna Core.