Guardian Swords++ are recurring items in The Legend of Zelda series.
Location and Uses
Breath of the Wild
Guardian Swords++ are the final class of Guardian Swords, surpassing Guardian Swords+ in both strength and durability. They are dropped by Guardian Scouts IV.
Mario Kart 8 Deluxe
A Guardian Sword++ was introduced in the version 1.6.0 update of Mario Kart 8 Deluxe. It replaces Link's Master Sword while the Champion's Tunic costume is used. Whenever a Trick is successfully performed, Link may draw the Guardian Sword++ briefly before returning it.
Link wielding the Guardian Sword++ from Mario Kart 8 Deluxe