It is said that when the Triforces of Dinner, Baby Yoshi, Ugliness, and Thin Air come together, they combine to form the Triforce of Triforce, a power that when bestowed upon someone could make anyone as powerful as WaPo... except it's only had observable effects on Link so far. Triforced Link is what happens when Link gathers the Triforces of Dinner, Ugliness, and Thin Air, and combines them with his own Triforce of Baby Yoshi. In this form, he is immensely powerful, his power level skyrocketing to Lower Undefeatable levels.
I just explained that TWICE. You know what, not doing it again. You want it, read the upper section. Let's just move on.
Gains awesome armor that looks like gold, but is actually a whole other, much stronger magical metal