TO kill a gray you should wait until it trows the spear at you, then hit it,it needs 3 hits to kill with the normal sword....
To kill a void eater, the safest way, i mean, it to w8 until it uses the anti-matter ray and hit him, otherwise he'll just use the explosion to kill you
 "Epic War 2"){kind=icon}
 "Amorphous+"){kind=icon}