You now have access to a Central Power Battery, either one in a color of your choosing if you lack a Lantern Ring of your own, or one for every type of Lantern Ring you have if you do.
In addition to providing an immense reservoir of emotional energy to work with, having access to the Central Power Battery also allows you to create Lantern Rings of the same color(s) as well, in turn allowing you to set up a Lantern Corps.