I didn't mean canon-wise, just if it had a story to play through. Always like having a reason to progress through games than just "let's kick some ass".
And is that honestly the gist of it? That's pretty good, hah.
There's a witch named Cia whose responsibility is to maintain the equilibrium of the Triforce. She grows jealous when her crush, a young soldier-in-training named Link, is only interested in Zelda. Drawn to her jealousy, a dark force overcomes Cia, driving out her good soul, and she launches a campaign against her former benefactors in Hyrule. She opens the Gate of Souls to usher in fiendish foes from other eras, such as Zant from the Twilight Realm. She also has her lieutenants: Wizro, who started as a ring that'd sap the strength of great warriors, and who was given a physical body by Cia; and Valga, who traded his soul to Cia in exchange for immeasurable power. The Gate of Souls is presumably how Cia commands enemy forces from different eras of Hyrule, I.E. the Bokoblins and Moblins of Skyward Sword, the Bulblins of Twilight Princess, and the Stalchildren and Stalfos of Ocarina of Time. Meanwhile, Link, the soldier-in-training, leads Zelda's army in the fight against Cia, accompanied by Zelda herself, and Impa, captain of the royal guard and sworn protector of the royal family. And where Lana is concerned, she appears to be a sister or "other half" of Cia, who saves Agitha when Agitha is cornered by enemy forces. Agitha gives Lana a special butterfly as a gift, which is stolen by Midna when she appears in Hyrule, seemingly under the influence of a dark power herself.