What if Link gets trapped in the Twilight Realm and can never escape.
At the end of the game, Link and Gannon start their final epic battle. Soon Link finds out that the only way to defeat Gannon is to kill him while in the Twilight Realm. During the fight, Link and Gannon jump back and forth between realms. Link tries to push Gannon through to the otherside while Gannon tries to kill Link and force him into the real realm. Link decides that he must destroy the gateway that allows passage between the two realms. While in the Twilight realm, he must somehow destroy the portal while as a whole. Once the portal is closed and their is no way for you to go back to the real world, Gannon gets pissed and shows his true might. Since they are in the Twilight Realm, Gannon draws upon the massive twilight energy and becomes more fearsome than any foe the real realm could produce. Luckily, Zelda helps Link out from the real realm and gives him the ability to be normal while in the twilight realm. After he kills Gannon (somehow), he is destined to roam a plagued realm till he faces a horrible death at the hands of one of the many monsters that lurk the realm.
Badass, no?