[@Oak7ree] I would say that dragons should either live for centuries at a time or just flat out immortal.

As for the magic-machine god, I would say that it shouldn't be just a strong robot or something but an actual god that people created. Like they used some extremely powerful magic and then used some new bit of machinery as a catalyst in which the magic was turned into a living god. More magical based than anything, allowing it to act more like a god with granting blessings and stuff so people actually believe in it. If you want it to be a bit more grimdark, look towards Bloodborne, could also have it be some monster people created.