it looks very nice, I think it's very solid and could have a good matchup against control, I am wondering about the nykthos though? A deck like this doesn't really need to generate lots of mana, just hitting land drops is enough.
I am also wondering about the shaman and ooze as 4-of for both. you need to ask yourself what your meta game is like? how often is your deck up against another graveyard strategy? Ideally, that is the role of golgari colours, to use a big graveyard. all other decks don't really use theirs like that so both of these cards are less powerful. I still say take the ooze to 3 of, and the shaman to 2 of, so you can fit in
reaper of the wilds. the hexproof on that thing has won me games all by itself just because it can't be removed.
I like this devotion to golgari deck, it looks much better though, just keep tuning it to the decks in your meta and it should do great