A prime source for magitech, oddly enough, is myth and legend, including that of the Ancient Greeks and their forge god Hephaestus. Among the most notable examples of Hephaestus' skill at artifice are the automata he built for himself and others. The best known of them was Talos, a bronze giant that Hephaestus as Europa's, and by extension Crete's, guardian on Zeus's behalf. Hephaestus also constructed the fire breathing bull automata collectively known as Khalkotauroi, the Caucasian Eagle (unless it was a child of Echidna) that was tasked to tear out Prometheus's liver every day, a score of bronze and gold tripods that fallow him to Olympus and many more than can be easily mentioned here.
At the same time within the annuls of Celtic
myth lies mythology's foremost example example of a magitech cyborg,
Nuada Airgetlám, or Nuada Silverhand. When the Tuatha De Danann landed
on the shore of what would later be known as Ireland, they learned they
were not alone. The land was already inhabited by a race of men called
the Fir Bolg or bag men. Nuada, the king of the Tuatha De Danann,
petitioned the king of the Fir Bolgs, Eochaid, for half of the island to
live on. Eochaid denied Nuada's humble request and war broke out, a war
that claimed King Eochaid's life. During the first great battle of the
war, the First Battle of Mag Tuired, the great Fir Bolg hero Sreng
challenged King Nuada to single combat. They clashed for the remainder
of the battle, until Sreng connects with a single blow against Nuada,
severing his right hand.
As beloved a king as Nuada was, the laws
of the Tuatha forbade those with missing limbs from the kingship, for a
king must be able bodied so he* can lead troops into battle and fight
along side them. So he stepped aside for a new king, Bres, a handsome
young half-Formor, with golden hair as bright as the sun. He was by by
most accounts a good and wise king, but Bres was little more than a
puppet ruler, a living tool which the Formor used to oppress and enslave
the Tuatha. Feeling desperate and desiring their freedom restored, the
Tuatha rebels scrambled to find a king to take their beloved but now
crippled Nuada's place, and no other names came to mind. So Dian Cecht
and his assistant Creidhne crafted a beautifully made silver hand to
replace Nuada's original lost appendage. This was no mere false hand for
Nuada, but instead an almost fully functional, if skeletal, silver
hand. Miach then covered the silver skeletal hand with flesh and blood
grown from its stump.
There's much more to draw on, but I feel this is enough for now.