You regularly undergo minor physical transformations when using your Arcanotech. Maybe it is a sign of health, that your body is rejecting the unnatural energy infused into it, but it causes you great stress.
Whenever you roll snakeyes (double-ones) on a Powers check you suffer from arcanotech trauma. This manifests as random changes in your body; you form seems to melt, while rivulets of strange, demonic energy twist about you.
Such an episode costs 1d6 shots in combat or 1d6 minutes of agony out of combat.
If you take this mutation several ties, the chance of trauma is increased by 1 in 6 each time - to 2 in 6, 3 in 6 and so on.