My Mill-Shake Brings All the Boys to the Graveyard (EDH / Commander) [Revision 16]

This deck is mainly focused on getting as many high value targets for Araumi of the Dead Tide into the graveyard as possible, and casting them for even more value!
To fill up the graveyard, we have powerful selfmill cards such as the amazing Altar of Dementia, which quickly fills our graveyard to the brim. In the graveyard, our most powerful creatures are our black creatures: They all have powerful ETB's, which either fills the board, destroys our opponets' boards or kill their creatures. Our blue creatures are powerful as well, but do things a little differently by drawing us cards, stealing spells and snatching creatures straight from the battlefield.
To make sure we can activate our commander, I've included the both Lightning Greaves and Swiftfoot Boots, so that she can hit the ground running while also being protected. Other artifacts include Panharmonicon for double up on our ETB's, as well as Sundial of the Infinite for keeping the creatures we get from Araumi instead of sagging them.
So as to not lose gas, we have plenty of good draw spells and creatures, notably Mulldrifter, Treasure Cruise and Dig Through Time. With these, we'll hopefully also drawn into our removal spells, some of which are on creatures like Ravenous Chupacabra for those Araumi encores!
Lastly, there's the land and ramp package, which doesn't feature anything special: Some mana rocks, some tap lands, etc. However, a card worth of note might be Bontu's Monument. The card doesn't seem that busted in this deck, since it only gives us a discount on our black creatures, of which there are only 15 (14, if we minus the Stitcher's Supplier, since it has no generic mana in its cost). However, we must not forget that we also get the cost reduction when casting our creatures from the graveyard with Araumi, and we'll also benefit greatly from the life gain, since three creatures will be summoned and killed with every encore!

So there you have it. Any advice is greatly appreciated, since I haven't built many decks myself. Cheers!