@GM Archlich: So I just checked and it seems they need to be the same bloodline. However, there is an Archetype for Bloodrager called Crossblooded Rager that lets me have two bloodrager bloodlines at the cost of a permanent -2 to will saves, and no +1 Will save when bloodraging. This can be offset by things like Iron Will, and greater and mighty bloodrage class feats. Though if you would allow the Archetype, I'd be content with keeping the penalty. It would after all fit with the characters theme.
So that means that I'd need to take the Bloodrager class instead of the Magus archetype. Which if I did that I'd be looking at switching my class spread. So the new class spread would be something like:
1st: Sorcerer 12 (Abyssal Bloodline)
2nd: Bloodrager 12 (Crossblooded, Abyssal+Infernal)
3rd: Bladebound Magus 12
This spread is easier to put together number-wise, I still get a good mix of arcane potential, and the flavor to play a mad drow is still there I think.