Ancient Bow and Arrow
When used, Link takes out the Ancient Bow and fires an Ancient Arrow straight ahead, hitting the first person in his line of sight. A small explosion occurs as the opponent is hit, damaging anybody else near the victim at the time. If it strikes a wall or floor, it will also explode, but the explosion deals less damage (35% → 20%) and loses a large chunk of its KO power. It works similarly to Zelda/Sheik's Light Arrow from Brawl and SSB4, albeit considerably weaker. It replaces Link's original Final Smash, Triforce Slash, from Brawl and SSB4.
When the move connects against a buried opponent, an unusual result occurs. While the move will deal damage and activate the explosion as normal, its knockback will not be expressed, and instead the victim will take the knockback of the move that buried them (which is usually used to calculate the bury duration). In the case of a thrown Pitfall, very strong set knockback will be dealt, revealing that the Pitfall uses a separate weaker knockback hitbox when connecting with opponents who are already buried, presumably to prevent this.
In The Legend of Zelda: Breath of the Wild, Link can acquire Ancient Arrows from chests or by having them made at the Akkala Ancient Tech Lab. When used on a Guardian, Ancient Arrows will deal heavy damage, and instantly defeat it if it is hit in the eye. If used on regular enemies, they will be defeated in one hit, but will not drop any loot. Link can also acquire the Ancient Bow from the Akkala Ancient Tech Lab, which is a high range bow with superior accuracy that deals bonus damage to Guardians.