Well, what are her main powers? If her main power is the robots with a bit of dark magic on the side then technology, but if she's a manipulator of the dark arts who just happens to have some robot minions to help her along then magic.
I am the Blaster, I have filled the role of Tank, Controller and Defender
Sometimes all at once.
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It's funny, you know? My mastermind, Dr Mechanibus, is himself a corpse kept alive by his armour. At least, he was. Now he's nothing more than a brain in a powered suit. I justified it as technology as that's what he did before, and it was the reason he still existed
I think I'll add to the confusion here...
I would go for the Magic!
If she was brought back to life by magic, then magic it is!
The technology part can easily be an "arcane-engineering" style. Think Arcanum (computer game) or Sons of Ether (from the P&P RPG Mage).
Just my oppinion.
To be honest for me it would depend more on the secondary than primary power set in that if the dark abilities are internally contained, literally a part of her, then there is no reason she shouldn't be magic. In fact I'd recommend it.
Even though she may be kept alive by technology and utilise technological creations as footsoldiers these can be classed more as external factors. Just because she's able to keep herself alive with technology doesn't mean she's any less a magical creature for it. Rather it shows she's willing to utilise any means necessary to keep herself alive.
Personally I'd lean towards magic origin, it just happens she currently has a need of technology. The technology may keep her alive but it doesn't change the core of her being.
Friends are just enemies that haven't betrayed you yet.
I don't think I can ammount to a reply more than "same old" that you've heard so many times before from my end:
Do what feels right.
As you might recall, I had the same problem with Kanae - choosing between technology (gynoids are technological reactions) and natural (technology and heightened abilities could be considered 'natural' for a gynoid), it really could swing both ways easilly and it took me quite awhile to decide.
In the end I picked Technology because I realized that it felt like it'd make sense for her to be upgradable (tech enhancements).
So rather than bouncing between wether the magical or the technological aspect make up her 'true origin', consider it like this: What makes more sense - that she replaces an elbow with one made of metal, or that she puts on a magical amulet. Are the robots built and gain more power through mechanical upgrades, or is it simply her sheer will and magical strength that empowers them?
Perhaps not the end-all solution, though regardless wether you see enhancements as IC or OOC, it might just help capture the spirit of the character easier. :>
I can pretty much just rehash what's been said.
For me it'd depend on if the magical resurrection was a one-shot and not the magic's gone, or if it is still present.
If the magic has become a part of her and still manifests through the powers then I'd go with magic origin.
If the magic was a one time occurrence and now it's up to the suit to keep things going then I'd choose technology.
Thanks for your views guys....this actually sparked off a whole story in my thread which I think adequately explains a "Magic" Origin. Once Augury comes online and I run things by her, I'll likely post it on the RP thread and make some sort of persistent story out of it.
Thanks again. 
I'm sure I've posted something similar to this in the past, but damned if I can remember if that was the case or where the link might be. At any rate, with Issue 9 on the horizon and a freespec coming on Tuesday, I've decided to make my Mastermind in advance to take advantage of the lovely goodness that is Inventions.
Unfortunately, I'm slightly confused as to what Origin I should go for with my character.
She's the - literally - ressurected husk of my old Mastermind, and after much oh'ing and ah'ing I settled on Robotics/Dark Miasma for her powersets (Mercenaries or not, I doubt few people would want to serve someone who amounted to little more than a sentient zombie). Her body is pretty much ruined at this stage and there's a fair old chunk of technology keeping her biology moving along.
This is why I'm confused. She was brought back by magic, kept alive through tech....yet her minions are robots, while her tangle with the underworld has left her with a few nasty tricks that she never had before. What sort of Origin do you think I'm looking at it? I keep flicking between Magic and Tech myself, but at this rate I might just toss a coin and see what I get from that.