Dillion was the son of a chieftain of Celts and Senua's friend and eventual lover. A warrior who managed to see Senua for who she was rather than her mental illness, his role in her life would eventually cause her to travel to the very depths of the underworld to save him.
Much of Dillion isn't seen outside of Senua's memories of his voice and face. He appears bearded with short, dark hair and medium build. During the game itself, Dillion appears as an auditory presence, a figure of pure blue light that appears and disappears at random and the owner of the disembodied head that Senua carries on her hip.
Senua first met Dillion many years before the events of the game when they were teenagers. Watching him practice his swordplay from afar at the root of a great tree, she practiced her own techniques for days and days. She eventually worked up the courage to meet him and show off the skills that she had learned from her observation. Dillion, sensing Senua's potential in combat, suggested that she come to watch him take part in the warrior trials and to bring her sword. A ray of hope ignited in her and Senua vowed to leave her father's oppressive rule and join Dillion.
After leaving Zynbel, Senua and Dillion spent the next several years together training diligently. In time, Dillion was able to learn of Senua's condition and did whatever he could to support her through it. He would aid her during her moments of blackout with no memory of what she did and would encourage her during moments where she was convinced she had brought suffering to her home. Friendship turned to love and Dillion rarely left her side.
One day, a plague struck, and Dillion's father died. Senua was blamed for the outbreak by the other villagers, and she became convinced through her psychosis that Dillion blamed her for his father's death. That night, Senua contemplated suicide, believing Zynbel was right. Dillion reassured her otherwise and implored her to fight the darkness. Wanting to make sure that her illness would never come between them again, Senua ventured out into the wilds in search of penance; Dillion made her promise to come back soon.
However, tragedy struck during Senua's absence: Dillion and the other villagers were attacked by the Northmen. While some were captured by slaves, most of them were brutally slain. Dillion in particular was sacrificed in a horrific manner, stretched out in a 'blood eagle' as an offering to the gods. Senua returned to find his half-decayed corpse and suffered a breakdown, her Furies screaming that she was responsible for his death.
After having learned of the Northmen's legends from Druth while in exile, Senua vowed to save Dillion's soul. She cut off his head and carried it with her, planning to reunite his body with his soul in the depths of Helheim and free him from the grip of the goddess Hela.
Hellblade: Senua's Sacrifice
While Dillion does not make a physical appearance during the game outside of his head, he does appear in many of Senua's memories of when they first met and of the times that he cared for and supported her. He sometimes appears as a figure of blue light, guiding Senua to where she needs to go.
At the end of her journey during the final confrontation with Hela, Senua comes to realise that the goddess is a manifestation of her inner darkness and that she never really possessed Dillions' soul to begin with. As she learns to accept the darkness as part of herself, she allows Dillion's head to fall from the top of Hela's sanctum and whispers a final goodbye to her love, accepting his death.
- Like with Galena, Druth and Zynbel, Dillion is portrayed as both audio and live video, super imposed into the game world.
- The Northmen's murder of Dillion, the "blood eagle", is an execution method outlined in skaldic poetry. The ribs are severed from the spine with a sharp tool and the lungs pulled through the opening to create a pair of “wings”. There is continuing debate over whether the "blood eagle" was actually used by the Vikings or whether it was simply a literary invention.