Ancient Bow and Arrow
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When used, Link takes out the Ancient Bow and fires an Ancient Arrow straight ahead, hitting anyone in his line of sight. It works similarly to Zelda/Sheik's Light Arrow from Brawl and SSB4. It replaces Link's original Final Smash, Triforce Slash, from Brawl and SSB4.
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 that deals bonus damage to Guardians.