Thanks for the chapters. Here are some ideas and questions that came to me. -But in TVD divine blood shouldn't be immune to witchcraft, so how could Dahlia, being only a strong but normal witch, bind her son with magic? -Dahlia will still come to get Hope right? -I don't know if there are but you could make him drink the blood of Alexander Corvinus, William Corvinus and Marcus Corvinus that way with his ability to purify he could eliminate the defects and problems of the virus that transformed them and obtain their powers and abilities ( you could either keep them as powerful as they are or weaken them), such as a stronger physiology (you could include the internal organs so it improves all its functions including intelligence) and enhanced senses and venomous bite as well as superior regeneration, all of this he could obtain it from the gods for having made the first sacrifice in a foreign land. -Will you have dominions over him as a god? But Baldur doesn't have mastery over wisdom right? -For when he becomes a vampire you could Weaken and/or eliminate their weaknesses from Thorfinn thanks to his demi-god status and his divine blood because the gods are not very influenced by the balance of nature, for example eliminating the need for a invitation to enter the house etc... -You could also make him closer and closer in power because the normal human part of him limited him and as he gets stronger he also grows into a god. -As changes he might undergo could increase his ability to learn and improve. -You could make him learn magic by discovering it thanks to his enormous curiosity. -He seems too young to be a Jarl now but you could bring him in as Ragnar's successor by having him marry Gyda that way he would still have power but without giving him too much power at a very young age. -When he returns you could start having him create his own army and increase his power, perhaps starting with a warrior band trained by him and making them become elite warriors over time. -During times when there is nothing interesting or anything like that you could have him explore the world with his army acting as both kercants and mercenaries as well as raiding and plundering, this way as well as learning everything he can about the Romans he could learn how to fight more efficiently on horseback from the Rus etc... basically learn everything possible.
You could make him a Jarl of another place when he is around 18 or 20 years old and start creating his own kingdom until he becomes the king of kings of the Vikings. When he is a vampire you could make him fake his death maybe by making him appear of the age he should be with magic and then go to other places for example after Vikings he could fake his death and come back when the Vikings Valhalla series starts etc... and so for all the times he decides to stop somewhere for a while. You could make him travel around the world becoming for example a nobleman, a king, an emperor, a tyrant, a colonizer, a merchant, a criminal, a pirate etc... and maybe take the same names as historical figures and if you want even change his appearance a little each time, then become anything he wants. You could have him start organizations of both normal people and supernaturals completely loyal to him. He should create a network of vagabonds and catahistorians to act as spies for him.