Im sorry to say that, but i strongly suggest you to rework the deck. The average cmc is kinda high with 4.0, paired with less ramp it will result in a slow deck.
Then it feels like there is a clear strategy missing. For example i would expect
Centaur Vinecrasher in a jund land destruction deck or in a Gitrog deck or something like that. With Meren u don't thow lots of lands into the Graveyards.
To improve it i would suggest to replace
Diabolic Servitude with other reanimator spells and get some more of them.
Diabolic Servitude is kinda bad for your deck, because creatures reanimated with it get exiled once they die. You are also very dependend on Meren in terms of recursion. If an opponent plays
Control Magic,
Gideon's Intervention or
Nevermore to get rid of your commander, your in serious trouble.
Then I dont really like selfmill in meren. If you get creatures in your graveyard, its fine. But everything else is (nearly) lost. Better try to get some more card draw (and discard creatures as reanimation targets) or cards that allow you to tutor into your gaveyard.
Buried Alive is a great example for this.
To future speed up your deck, what about
Yavimaya Elder? reusable card draw and ramp. And what about
Ashnod's Altar? Its nearly a must have in Meren, since its a sac outlet for your creatures and even produces mana.