The Advent (降臨の日 Kourin no Hi?, Day of the Descent) is an ritual event in Tales of Berseria. As the translation of the original title suggests, it was the day of which the descent of the malakhim race. Many of the malakhim had descended from the skies and on to the Wasteland world, as well as the ones already on its surface becoming visible to regular human beings.
The event is shown as the prologue of Tales of Berseria. The event occurs three years prior to the main story. On this day, the younger brother of Velvet Crowe, Laphicet Crowe, has had a conversation with their brother-in-law and adoptive brother, Arthur, about the upcoming event of the Scarlet Night. Laphicet discusses with Artorius about the revival of the great Innominat, to which was written that "two souls with strong resonance and hearts free of malevolence and bad will are required". Artorius further clarifies to him that his unborn child with Celica Crowe acted as the sacrifice that completed the ritual. He further mentions that this would allow him to be able to form an array of exorcists.
Upon hearing this, Laphicet asks of Artorius if he could act as the sacrifice to complete the ritual, stating that he was bound to die due to his own chronic sickness lasting all his life. The completion of the ritual would result in the resurrection of Innominat. To this Artorius agrees, the two of them deciding to keep it a secret from Velvet because of the grief and misery it would cause her naturally, and that Artorius would rather have it had been through the following of his "plot". Later on, during the event of the second Scarlet Night, Artorius and Laphicet head to the altar sanctum shrine located not far from their hometown Aball. When Velvet arrives to see both her family, Artorius and Laphicet all right, Artorius casts a exorcist binding arte through commanding malak Seres to which he then strikes his sword through Laphicet. In the localized version of the game, Laphicet is tossed into the air where a binding cross severs him. This was a change made by Bandai Namco Entertainment due to its brutal nature, and left as it is would result in the ratings for the game changing.
After being released from the bind through her struggle, Velvet catches Laphicet until the two are shoved and dropped into the altar. This results in a draconic creature resting inside to consume and devour her younger brother with the aftermath of it being that Velvet becoming a therion, a variable form of a daemon. This in turn leaving Velvet both heavily angered and grieved, manifesting her daemonic arm and charging at Artorius in rage. Velvet devours the daemons praying on her with her left arm, these daemons originally being the villagers of Aball who had become corrupted. Completing the ritual and the resurrection of Innominat, further calling down the other malakhim to the world and allowing the normal human beings to perceive them. Through this, Seres was able to gain back her abilities to restrain herself and later decides to leave Artorius and his ways.
Artorius knowing the link between Velvet's powers as a therion and Innominat's source, captures the collapsed Velvet and locks her away at the prison island of Titania for three years until her breakout.
It is later discovered in-game that the result in the therion creatures vary because they are all chosen based on the emotions the one who becomes one had bore. Velvet referring to herself as the worst one.