Does Gray Merchant of Asphodel Count Itself?

Question is does gray merchant count towards the devotion, "enters the battlefield" mean that he's arrive or somewhere inbetween? It is on the battlefield at that point, so, yes, it does count itself.

How does Gray Merchant of Asphodel work?

When Gray Merchant of Asphodel enters the battlefield, each opponent loses X life where X is your devotion to black. You gain life equal to the life lost this way.

Does hybrid mana count towards devotion?

A hybrid mana symbol adds one to your devotion to each of its colors and one to its combination of colors; it does not add two devotion to its combination of colors. Mana symbols on permanents with devoid still count; devotion just counts mana symbols, not the colors of the permanents themselves.