The titular group of The Seven Deadly Sins is revered and feared for being one of the most powerful groups of knights in the entire kingdom of Britannia. Each one of the Sins is a formidable warrior with their own unique abilities, however, each of them also possesses a signature weapon that increases their strength even further. Entrusted to them by King Liones, the Sacred Treasures are magical weapons unique to each member of the Sins.
These weapons vary dramatically from one another, so let’s take a look at their history and what they can do for the Sins who possess them.
King's Spirit Spear, Chastiefol
King uses this weapon, forged from the Sacred Tree in the Fairy Realm. This was the first Sacred Treasure to be introduced in the series, as well as the Sacred Treasure that is most frequently used by its Sin. In fact, King is utterly helpless in battle without it. It commonly takes the form of a large, green pillow, although it changes forms quite dramatically.
The Chastiefol can also take the form of a large, bear-like creature that aids King in battle. As the name suggests, the Chastiefol can take the form of an enormous spear, capable of several different configurations. A multi-purpose weapon, King's true power is almost entirely dependent on his Sacred Treasure, and it's one of the most powerful of them all.
Diane's War Hammer, Gideon
Diane owns this gigantic hammer that stands as tall as she does. 10 years before the start of the series, after the Sins fled the kingdom, Diane lost possession of her Sacred Treasure for reasons unknown. It eventually turned up as the grand prize for winning the Vaizel Fight Festival. When Diane regains possession of her Treasure, the weapon's power is overwhelming.
Diane's ability to control the earth increases exponentially when she has the hammer, allowing her to essentially level the entire town of Vaizel. Additionally, the hammer can act as a magical lightning rod, absorbing offensive magic and dispersing it into the ground. However, Diane prefers not to utilize this ability, because it's harmful to the Earth and any creatures living in the ground.
Gowther's Twin Bow, Herrit
Gowther possesses the most unique Sacred Treasure, in that it's not a physical weapon, but pure energy. Gowther can summon this magical bow at will, and fire it however he pleases, not constrained to the proper technique required by a real bow and arrow. The energy used by this weapon reflects Gowther's own abilities, as he can use his arrows to alter people's minds. He has used it maliciously to manipulate people's memories, as well as practically by using it to render specific people unconscious. While his Sacred Treasure isn't as destructive as the others, it's still among the most powerful for its tricky capabilities and ability to influence a large group of enemies instantaneously.
Ban's Holy Staff, Courechouse
Ban fittingly possesses an absurd Sacred Treasure that resembles a set of tricked-out nun-chuks. The weapon is made up of four segments, with a spike at each end. Like Diane, Ban lost possession of his Treasure for an extended period of time after it was stolen from him when he was captured by the Weird Fangs. Courechouse has no need to follow the laws of physics, as its individual segments can distort, lengthen, and move at unnatural angles and speeds, allowing Ban a wide range of attack.
The Holy Staff itself is essentially an all-around power boost for Ban, increasing his strength and mental fortitude, as well as bolstering his Snatch ability. His technique is normally fairly limited in terms of the damage it can inflict, but the powerup from Courechouse even allowed Ban to Snatch the heart right out of a demon.
Merlin's Morning Star, Aldan
Merlin is seldom seen without her Sacred Treasure floating nearby. Resembling a crystal ball, the supremely powerful mage can use her Treasure for all sorts of magical techniques. Used in conjunction with her magic, Merlin can spy on enemies and she's even capable of transferring her soul into it in order to avoid harm or death itself. Easily the most versatile of all the Sacred Treasures, Merlin's Treasure does what she wants it to do, rather than any preset abilities like the others.
Escanor's Divine Axe, Rhitta
Escanor owes his Sacred Treasure a great debt because it's the only thing that prevents everything and everyone around him from burning to ash by absorbing the excess heat he is constantly emitting. Able to summon the axe to him from anywhere, Escanor used to keep the enormously heavy and poorly balanced weapon mounted in the wall inside his cave bar. The blade resembles a crescent moon, and a small handle at the end allows Escanor to swing it freely, a testament to his incredible strength.
Even though the axe is constantly absorbing Escanor's energy, he can pump further power into it in order to stay in his daylight form during the night, something he is otherwise unable to do. Rhitta is as insanely overpowered as Escanor himself, as the mighty warrior can use it to unleash a burst of energy so massive and powerful that it could be mistaken for the actual Sun.
Meliodas' Demon Sword, Lostvayne
Meliodas is so powerful that his own Sacred Treasure is pretty low-key in comparison to the others. The Treasure is a short, curved, ornate blade with Meliodas's Dragon Sin insignia imprinted on the handle. The silver blade is said to turn red when Meliodas wields it with his full power. The weapon allows Meliodas to create clones of himself, who are capable of using his techniques, like Full Counter. However, Meliodas's total power is divided amongst however many clones he makes. This disadvantaged ability makes Lostvayne far from the most powerful Sacred Treasure, but considering who it belongs to, that's probably for the best.