What happened to Thanatos eyes??? I know he is the God of Dead so here my theory, the Goddess of justice and the Libra sometime draw as eyes cover by something so she can not see in order to judge a person fairly . So can it be the same case for Thanatos, to not see mean to judge a person equally not by the status of that person rich or poor???
There maybe some confuse here, I guess. Since Thanatos, is more like a judge for those who died so maybe cover his eyes in order to let him have a fair judgment on every souls. And Libra also in the same case I think.