That means you can afford to splash out a little bit more in black for cards that provide options and won't ever be dead weight in hand (obviously once you can cast it, everything with a cost can be dead when you can't pay it...)
Canoptek Tomb SentinelCanoptek Tomb Sentinel can get in some decent damage, but thanks to vigilance and it's ability to exile a permanent if it enters from graveyard, it makes for a decent deterrent for attacks
Samut is a six mana Legendary Creature that costs three generic, one white, one red, and one green
We can only afford 3 Game Changers anyway, and the choice of 1 mana tutors or moxen is taken away, leading to our inclusion of Deflecting Swat, Demonic Tutor, & Jeska's Will as more obvious than they'd otherwise be
Crab might seem odd here, but we have a lot of ways to get lands into play from our library, so it turns cards like Crop Rotation, Harrow, and Growth Spiral into mill spells
Alternately, if your deck plays discard or countermagic, just wait the extra 1-2 turns to play your important threat with mana up for a same turn TS or Spell Pierce