Follow TV Tropes
Gilgamesh's Ea. Look it up. Leveatin from the SMT series a sword made of flames that can wipe out all life on a planet. As well the Sword of Miskado the cannon weapon of Aleph from SMTII, that thing was used against YHVH. And Killed Satan.
I give you Akai Katana Shin:
The Monado is anything but sane. A laser bladed BFS that only few can control without it going berserk (and even then, those not chosen by it will get weakened, and eventually killed, trying) capable to control the world's essence directly, to allow its chosen wielder to see the future, and to cut through anything he wishes (eventually).
Oh, it's also batshit xenophobic, which kind of comes with holding the soul of the local Complete Monster Evil God, but damn is it stylish!◊
Crisis Core. Umbrella.
I nominate this. A humble Arabian sword. Nothing special. But it is badass to be using a sword in a spunkgargleweewee game.
Community Showcase More
How well does it match the trope?