Oath

Oath is a term appearing in Tales of Zestiria and Tales of Berseria. It is a powerful arte that grants the oathtaker special traits at the cost.

Description
While mainly seraphim, and to an extend malakhim, take on the oaths to acquire powers they don't usually has access to, humans are also known to take on them. Depending on what was chosen by the oathtaker to sacrifice for their newfound powers, failing to stay true to it may come with dire consequences.

History
Melchior Mayvin has taken an oath to live for centuries. Claudin Asgard has taken an oath that he will not kill in exchance for long life. Seres has taken an oath that in exchange for her life a powerful power would be born, resulting in the formation of the Sorcerer's Ring after Velvet Crowe devours her. After Maotelus falling prey to Heldalf resulting in the loss of Silver Flame that can quell malevolence, Lailah took on the oath to not speak about the events leading to Maotelus' downfall at the hand of the Lord of Calamity at the time of Tales of Zestiria in exchange for the power over Silver Flame.

According to Tales of Berseria World Guidance, Magilou took on a special oath and became the Storyteller of Time since she started to care and explore the world, resulting in her outliving other humans.