I agree with you capsocrate that just reading the card, Asterios may seem very strong, to the borderline of too strong.
On the other hand, his attack power is not that great : 3 attacks of 3, not upgraded by heigth, and he have to walk to contact to make them (height slow him down, and he does not profit from the road). Q9 has the same power output, but safely from 6 range, behind a screen of rat, with a defense of always 7.
Most squads hit harder than him, with more flexibility.
With his defense of 3 against heroes, large squads and special attacks, he rolls only 3 defense dice more often you would think.
Sure, against only aubrien archers on a totally flat map, he slaughter them, but it is the ideal situation for him, like if DW 8000 was against only venoc vipers.
Whatever, I'm really looking forward to heard how you managed to use him or counter him when you'll playtest him !
I had very interresting playtest with him, where my opponent carrefully made both heroes and squad advance, with squads in front to lure Asterios into charging and Hero behind to jump on him if he charge. It was difficult but really fun decisions to take !