I think the 6+ invul. is a bit too far. However, the 6 arms sounds like a Daemonic Mutation to me (though I know it's not), and an extra attack would be very appropriate, I think.
Let me ask this: what style do these abhumans fight in? Are they geared for close quarters? Short-ranged fire-fights? Speed?
And keep in mind, for people to want to play it, it has to be something that hasn't been done before. So, try for something original in playing style.
__________________ Lord of Fluff and Blood Angels Herald of Nurgle "I wield my power with the Emperor's Authority. Those who would say that I am 'radical' merely have minds too small and impotent to realize all the weapons at their disposal. Do not question my methods on account of these so-called 'Puritans'." -Inquisitor Mathias Rosenadel |