The Winged Sword「天翼の剣 Ten'yoku no Tsurugi」 is a holy weapon passed down for generations among the Celestials.
The Winged Sword possess a long feather-shaped blade over a handle with several blue spheres encrusted within it and two feather-like ornaments near the base of the blade.
The Winged Sword was bestowed upon the Celestials 3,000 years ago by the Great Oshiro in order to seal the Indura and the Six Knights of Black inside the Egg Rock of the Sky Temple. Since then, the sword was passed down for generations by Head Warriors of the Celestials, awaiting the arrival of the Time of Ruin in which the demons would achieve liberation, attacking the Celestial Clan.
The Winged Sword was located inside the Sky Temple, awaiting to be passed down to Solaad in the ceremony. Ellatt goes in seach of it when Dahaaka was killing the Celestials, but Meliodas kills him without the need of it.
When the Six Knights of Black are released from the Egg Rock, Zoria uses the Winged Sword to fight Bellion, managing to cut off one of his arms. However, Bellion manipulates the severed arm to force Zoria to pierce Meliodas with the Winged Sword, resulting in Meliodas being put in a comatose state.
The Sword is later removed by Solaad, who decides to use it to save his people from the demons.
Understanding the true power of the Winged Sword, Solaad combines it with the power of his Ark in an attempt to seal Baruja, an Indura that breaks free from the Egg Rock. This, however, fails when Bellion gives his own soul to the Indura, giving it enough power to avoid the seal. Solaad then manages to put the entire Celestial Clan on his side and unites the power of all of their Ark, giving the Sword the power to contain the Indura. This let the Seven Deadly Sins to combine their powers into one single attack that destroys the Indura and puts an end to the Time of Ruin.
The Winged Sword was created to fight the Demon Clan. It is capable of wounding high-ranking Demons without allowing them to regenerate. Its true power is the ability to seal demons, to be used in conjunction with the Ark of the entire Celestial Clan, even having the power to seal an Indura.
The sword can only by handled by the Head Warrior of the Celestials. Even Escanor, who possesses the power of Grace, couldn't wield it.