Triforce of Wisdom
Zelda traps the opponent with the Triforce of Wisdom itself. It is only able to affect one opponent at any given time. However, it is notoriously hard to escape from due to the size and strength of the move's vacuum hitboxes, making it almost guaranteed for an opponent to get caught within it. If the moves ends with the opponent below 100%, they are sent flying out; otherwise, the opponent is instantly KO'd. As the move itself deals 67%, it can guarantee a KO at very low percents. As a result of its strengths, it is rather infamous for being extremely effective in a 1v1 setting.
In Stamina Mode, if an opponent is caught by the initial vacuum and loses their last stock because of it, any other nearby opponents will still be sucked towards the Triforce and will not get affected by it, apart from the move constantly attempting and failing to drag another victim into the Triforce.
The three pieces of the Triforce are a sacred relic in The Legend of Zelda lore, with legend stating that anyone who collects all three pieces of the Triforce will be able to grant themselves a wish. It is stated in A Link to the Past that the three Golden Goddesses, Din, Nayru, and Farore, left it behind after they created the land of Hyrule, and Hylia was tasked with watching over the land and the Triforce.
The three pieces of the Triforce are spread across the main characters in the series - Zelda holds the Triforce of Wisdom, the left piece; Ganondorf holds the Triforce of Power, the top piece; and Link holds the Triforce of Courage, the right piece.
The Final Smash is very similar to the final battle against Ganon in Ocarina of Time, where Zelda used the power of her Triforce to trap Ganon so that Link can deal the final blow.
In Breath of the Wild, Princess Zelda is said to have a "sealing power" that she has been unable to harness for most of her life, which causes much strife between her and her father. She eventually learns to use this magic. When she uses it on Dark Beast Ganon following the final battle, he disappears in a similar vein to this Final Smash, although it is a bubble shape with the entire Triforce overlayed instead of only a single piece of the Triforce.