Severino Agonni was a mafia boss and the head of the Agonni family. He was found murdered at a warehouse in the Merseyshore docks.
Severino Agonni was the head of the feared Agonni crime family. Four years prior to the story, they had betrayed Keelan Makepeace, which would later cause his death. On the other hand, his paranoia about there being an assassination against him led him to hide himself and three of his men at the Merseyshore Docks warehouse. Around that time, Barbarossa Sassina, his right hand man, fell in love with Diane Makepeace, a young woman. Rumours soon spread across the Agonni family that Diane was a ghost.
In an attempt to bring attention to New Scotland Yard and to get revenge on the Agonnis, Diane manipulated Sassina into killing the other Agonni Family refugees. Out of his love for Diane, he accepted to execute the plan. After killing Boyle and Fassi, Sassina and Agonni met in the latter's office, with the former having a rope in his hand. Before Agonni could ask questions, Sassina proceeded to strangle him with the rope, with the struggle breaking his neck. Under instructions given by Diane, he poured petrol/gasoline on the body and set it on fire. Sassina placed a puzzle piece near the burning scene, mimicking the fourth of the Jigsaw Killings.
However, Sassina met his end as well when Diane came to the warehouse, and the two proceeded to make out. Uttar Mistry, who had just came to the warehouse to deliver take out food, saw the two together. However, Diane stabbed Sassina in the back with a poisoned knife, which killed him later on. This confused Mistry, making him think that Sassina had witnessed him and was angry, and he ran away in fear.
- His name is a play on "sever agony", which is likely a reference the severe way he was killed.