Cursed from the beginning, damned in the ending, Blaine has literally been to Hell and back. Plagued by the undead and then adopted and abandoned by the infernal. He has had nothing other than the opportunity to sell his soul to the highest bidder when all he's ever wanted was to amass the greatest power and wealth available to him.  

That being as it is, even a bastard has had a moment or two of goodness when those close to him have mattered more and his own sacrifices have been made.  Maybe that's what landed him in this situation, and maybe now he'd like to make up for it with vengeance or perhaps further atone with more retribution.  The story hasn't ended yet....