Commandment

A is a unique power created by the Demon King over 3,000 years ago, and bestowed upon ten different elite warriors of the Demons. There are ten in total and each has a unique curse of absolute power bestowed upon anyone who breaks its rule. After becoming the new Demon King of his own volition, Meliodas has destroyed all of the Commandments.

Overview
The Commandments are a set of ten decrees that were created by the Demon King when he took half of his power and split that into ten fragments to create the Ten Commandments, who derive their group name from their powers.

Each Commandment has a specific rule that, if broken, will place a specific curse on the victim(s) depending on what the Commandment itself is centered around. The power of the Commandments is absolute and affects anyone who breaks its rule, even the wielder itself. However, anyone who has another Commandment is immune to all others except their own. Those who were given a Grace or a divine blessing by the Supreme Deity are also immune to the Commandments’ effects as well.

The curses will only be lifted if the victim defeats its wielder or at the victim's death. The Commandments can be removed from their wielder using a special spell, but only if he or she gives their consent or if they are left powerless, unable to fight or die.

Absorbing a Commandment turns any non-demon race into a demon, giving them the standard demonic powers as well though in the case of a goddess while gaining such powers, their souls and minds would be devoured and warped by the Commendment due to being the polar opposites of demons. Though Mael, the only goddess to receive a Commandment, was bestowed one after his memories were altered by Gowther and his doll so it’s unknown if the same effect applies if he had his real memories intact. Moreover, if anyone, demon or not, tries to take in more than one Commandment, it would destroy them. Monspeet himself said only the sons of the Demon King, Meliodas and Zeldris, could survive such a feat, but it is revealed that Mael, as Estarossa, is capable of doing so too, but at the cost of warping his broken soul even more and in the end losing his sanity and failed to fully take in four of them, meaning Meliodas and Zeldris, as the only true sons of the Demon King, are the only two beings who can successfully take in all ten of the Commandments.

After Gowther’s memory spell wore off and Mael regained his memories, his body holding three Commandments took on a mixed appearance of a goddess and a demon where his left half is that of a demon and the right is that of a goddess. In this form, he’s able to use both his holy and demonic powers and even combine them together. After absorbing a fouth, Mael was able to materialize the Commandments in physical forms and use them for various attacks.

When Gowther entered into Mael's mind it is revealed that the Commandments themselves seem to have a certain degree of sentience, as they attempted to manipulate Mael into handing over his body to them and also attempted to banish Gowther from Mael's mind to prevent him from interferring. However despite their sentience and power, Gowther has stated that they cannot make use of their immense power on their own without a host to use it for them.

Meliodas states that by absorbing all ten of the Commandments, he can reach a level of power equal to that of the Demon King and Supreme Deity, as he is doing so to end the curse placed on Elizabeth Liones. However, it is later revealed that absorbing all the Commandments really means becoming the new vessel of the Demon King, this being the true reason why he created them.

After absorbing all the Commandments, the vessel can undergo changes, as Meliodas and Zeldris' appearance physically ages into an adult.

The Demon King stated that the Commandments can feed directly to him information of the holders, to keep an eye on them, as to prevent any rebellion attempt against the Demon King.

After the Demon King was defeated by the Sins, Meliodas went into his Demon King form and destroyed the commandments.

The Ten Decrees
NOTE: Bold denotes original possessing member in the current Ten Commandments formation, if different from the previous known holder.

Other possessors
The commandments have also been held on by several previous predecessors, but they have been relinquished of the commandments.
 * Aranak (either Repose or Patience; killed by Meliodas)
 * Chimera Indura (unknown; turned into Indura)
 * Zeno (either Repose or Patience; killed by Meliodas)

Techniques

 * Mael takes the Love Commandment and uses it to create an incredibly destructive explosion. The effects of the Commandment turns any pain and suffering in the opponents into pleasure, lending them to grow sleepy and finally die.
 * Mael takes the Truth Commandment and uses it to create a bell capable of dispersing any illusion.
 * Mael takes the Reticence Commandment and uses it to craft a scythe that brands anyone hit with the cursed seal of the Commandment, sealing their magic.
 * Mael takes the Purity Commandment and uses it to create a big incense which smoke make people to be immobilised by a great preassure and suffer hallucinations of what their hearts truly desires.

Trivia

 * Each Commandment is directly inspired by one of the 10 Commandments of the Bible :
 * "You shall have no other gods before Me" corresponds to the Commandments of Piety 
 * "You shall not make idols" corresponds to the Commandments of Faith
 * "You shall not take the name of the LORD your God in vain" corresponds to the Commandments of Reticence
 * "Remember the Sabbath day, to keep it holy" corresponds to the Commandments of Repose.
 * "Honor your father and your mother" corresponds to the Commandments of Love
 * "You shall not murder" corresponds to the Commandments of Pacifism.
 * "You shall not commit adultery" corresponds to the Commandments of Purity.
 * "You shall not steal" corresponds to the Commandments of Patience.
 * "You shall not bear false witness against your neighbor" corresponds to the Commandments of Truth.
 * "You shall not covet" corresponds to the Commandments of Selflessness.