His motivation is fairly simple, due to his personality he doesn't bind himself to a family or friends so keeps to himself and has done for pretty much all of his life, aside from a few friends that he has made along the way. Considering how long he has lived, he's clearly not a very pleasant man. His goal is self-perfection, to master every extent of his power which he still hasn't done, due to how difficult it is to master Blood magic. Also, he wishes to start his own "cult" I suppose you could say called the circle of blood, where he teaches this magic to others who take interest and forms his own seat of power within that cult.

He has ties to Romulus, Romulus being his closest friend and also respects Romulus for his power. So with the aid of Romulus he will try to forge his blood cult and give himself a stand point in the world, with people forged under his own image of perfection.

(I think that's what you meant at least.)

Also I thought there would be no better representation of Jericho other than Vlad, League's very own vampire x]