Dominik was born hundreds of years before the start of the story. Despite being born the son of the elder Dagan his status as an elder was not guaranteed. To this end he tried to court Katherine, though she was already in love with Samuel.
He approached Samuel in the human's final moments and offered to turn him, on the condition he split from Katherine. After Samuel complied Dominik stabbed him.
Before he can finish them off however Cross arrives. Attacking him they fall into the basement of the church. Here Dominik tries to interrogate the zompire. Andrius arrives however and impales his brother, then allowing Cross to feed on Dominik's blood.
Dominik, now turned into a zompire, withdraws to the darkness.
Still in the church from before, Dominik is approached by Jess, Doc and Jake. After mentally conversing with Doc, Dominik agrees to head with them to New Hammerston.
Locked up in Doc's lab, Dominik comes across Joe in the Dream World. Here he offers to return Joe's body to him on the grounds that Joe will one day help him. After Joe agrees Dominik assists Joe in overcoming Inner Joe.
Despite Doc having locked him in his lab Dominik easily manages to escape, turning several guards into zompires while out.
Later Dominik escapes with Doc into the wastes.
Dominik is shown assisting Doc in establishing a new lab in the wastes.
Dominik is shown in a flashback by Samuel.
He is properly shown later on, where he is with Doc setting up their laboratory. Dominik explains to Doc that a group from New Hammerston is on their way to find him. Though Doc is apathetic to the group, Dominik is curious as to see his response when he meets them.
After Jess' group entered his lair, Dominik approaches Rosa in the Dream World. He notes that she is quite strong, and has somehow overcome the zompire affliction (despite being bitten by Cross). He thus orders his minions to capture her.
Dominik soon arrives in person to meet Jess, along with Doc. After Jess refuses to leave Dominik prepares to fight her. Though he lets Jess have the first strike, she is no match for Dominik and he soon subdues her.
Following his fight with Jess he appears to have made off with Rosa, though she manages to overpower him. When he is next shown he is in a state, having been soundly punished by the younger vampire. Upon Doc's arrival Dominik explains how the races of the world are in a stable balance, though he is once more speared by Rosa. As Doc and Rosa leave Dominik mentally contacts her, explaining how she will be rejected by the townspeople and forced to return to him.
Dominik seems to be the standard vampire archetype, being at best apathetic towards humans.
Dominik seems to have had few companions, though he had several disciples (amongst them Genovera).
Despite being brothers the two appear to have despised each other.
Dominik and Doc seem to have a mutual respect for each other, Dominik interested in the human for the possibility of a cure for the zombie virus, Doc interested in the zompire for research purposes.
Dominik has shown himself to be a powerful figure. He was easily able to deal with Harry, Jess, Inner Joe and even Cross. Despite this he seems to still be weaker than Andrius.