Although four mana is quite a lot, Omnath, Locus of Creation stabilizes games incredibly well and does a bit of everything
If youre playing any Songs while youre at it, Cinderella, Ballroom Sensation lets you exert Cinderella, so she counts for three when you cast your Song, which is a nice little bonus to your deck
Whenever one of your Dragons attacks, Ojutai lets you tap an opponent's nonland permanent and prevents that permanent from untapping during their next turn
While this deck is a go-wide strategy, we wanted the tokens you make to be more diverse than 1/1 creatures (though the deck still has plenty of those expressing various kinds of soldiers and raiders)
Im somewhat excited to force mono-black at every draft table I sit down at, but thats because Im a bad person who cant say no to Nightmare
It's versatile