Every Weapon In Wonder Woman's Arsenal
9. Her Sword From Hephaestus
In recent years, this is the weapon most commonly associated with Wonder Woman. Called the Sword of Athena, it was forged by Hephaestus, the armorer of the Greek gods, and gifted to Diana.
The sword can harm beings that would otherwise be immune to physical weapons due to the magic imbued in it. The quality of its forging is such that it is sharp enough to shave electrons from an atom, as Diana explained in Kingdom Come.
In fact, in that comic Superman was indeed cut by the edge of the sword (although he does have a vulnerability to magic, which played a role in his injury.)
Diana has used this sword extensively in the DCEU movies, with the prop sword used by Gal Gadot in these films inscribed: "Life is killing life all the time and so the goddess kills herself in the sacrifice of her own animal," which is a quote by Joseph Campbell. Campbell is credited as the creator of the myth of the 'hero's journey', so his quote is entirely appropriate.
You won't find a melee weapon much deadlier than when this sword is being wielded by Wonder Woman.