uhhh preds have crazy technology, theres probably a computer in that thing for flight much more advanced than the stuff in our newest jets, which wouldnt be able to fly without a computer CONSTANTLY making corrections. id imagine preds dont cloak when fighting aliens cause aliens could see them anyway and about the blood on the shuriken, maybe the shurikens are resistant to the blood and the blood just flings off them, like water on a rain-x'd windshield