While the Buster Sword is better some might call it busted The Masamune is more niche but still hugely powerful with the right deck strategy
223 Piglet, Pooh Pirate Captain Super Rare 223 Yen Sid, Powerful Sorcerer Legendary 224 Mulan, Elite Archer Legendary 225 Mickey Mouse, Playful Sorcerer Rare Disney Lorcana: Ursulas Return Foil Checklist 204 cards
While I know that most planewalkers die from going to zero loyalty, there are occasions where they just outright get killed (see also Lethal Scheme)
Its enough damage to kill almost anything, but you could also point it at your opponents smallest creature (or most damaged creature post-combat in some bizarre situation) to force through four points of damage
Khans of Tarkir just dropped, everyone was clamoring to build Commander decks using the new wedge-aligned 3-color creatures, Siege Rhino was a menace in Standard, and WotC was releasing their third ever Commander product