Responses

i think that it was the literal meaning for his "life" and "death" analogy. Because he is the ruler of the underworld and from what I can imagine, I don't think he could "die". That skeleton is probably a metaphor for what he really feels inside: "dead" and "not alive". While the Phoenix's symbol is about rebirth and "life", his is "death".
╮( ̄▽ ̄)╭
OMG when fourteens hand turned skeletal my heart dropped...please tell me he just lost power or something and didnt die