I wouldn't cut Hippie for this. Random discard is such a brutal effect. Wizard's isn't ever going to print more cards that do what Hippie does. New Drana is better later in the game (especially with a board presence), but there's no way it's a better T1 play off of dark ritual.
Herald makes a 2/2 that would otherwise be chumped hit like a hasty 5/5 flier when you Bestow it. Which gives you a 3/3 flier when THAT dies. I don't have room for it, but Herald is really a very underrated card. I do, however, prefer Master of the Feast to it.
I might cut Master for this. They both represent a lot of damage when they go unblocked, but I think Drana has a better chance of providing lasting value if she's dealt with after only a couple of swings, in addition to not giving up the card disadvantage or dying to disenchant effects. I like Master a lot, but I think Drana might be better in the hard aggro support plan, thanks to her Slith/Curse effect and the impact it has on your other attackers.
Nighthawk still does work for us here. The defensive abilities are most welcome in a color that really needs the lifelink and has the rest of its 3-drops focussed more on their offensive capabilities. Nighthawk still plays a good role for us in control decks, and when mitigating some of black's numerous lifeloss penalties.
I think I would prefer to cut Silumgar Assasin or even Vampire Nighthawk from your list before considering cutting Master of the Feast. No way this fatty beater is the worst of your black 3-drops. I cut Nighthawk a while ago and don't really regret it so far. It's a good card, no doubt, but it just doesn't have any true place where he could shine. It's just a good overall card without so much flavour.
There are way too many ">" symbols in that list IMO.
Nighthawk is a solid card but it's only ever "good". It's very rarely great as it has next to zero synergy with anything. It's just an efficient card with useful abilities. Dauthi Maurauder is very good if you support black aggro and very terrible if you don't. Ranking it without context makes zero sense to me. Fleshbag is similar. It's valuable removal but edict effects have high variance, so YMMV there depending on how much token and swarm strategies are supported and played in your cube. Geralf's Messenger is the most powerful card in a vacuum as it represents pseudo card advantage, a guaranteed 4 life from your opponent, and it a pretty nasty beat stick. But it's mana cost makes it prohibitive and so really only a great card if you support mono black (otherwise it's a 4+ drop).
New Drana is great with a team, but it's a slow anthem requiring that it survive at least one turn (and make contact with the opponent) before it's anything better than a 2/3 flyer. If you only have one other dude, I think nighthawk's life gain and death touch make it better personally. So the question is, do you have a +1/+1 counter theme that this card would synergies with? Or do you routinely see 3 creatures swinging by T4 in your meta? If so, new Drana will be good. If not, it will likely not outperform what you are already running.
Swapping this in for Master seems reasonable though. The drawback on that card is pretty severe, and one swing of this card with a friend gets you to a better place without the horrendous drawback.
I think cards like Grim Haruspex or Mardu Strikeleader might be my cut. Hearld of Torment is a 5 drop by my estimation that as an alternate 3 drop mode, not the other way around, and it is one of the best in that slot. I have a hard time cutting nighthawk, the lifelink plus evasion is all the synergy my black decks need, and deathtouch is sorely underrepresented in cube.
Master of the feast could be a cut for some as it can lead to some feel bads, but I love high risk reward creatures.
I would cut Grim Haruspex but it just doesn't feel like it fills the same roll. Grim Haruspex is great in pox strategies and fuels symetrical disruption strategies like Blood Artist does. Drana is just an efficient creature that's good in tokens or aggro. I would probably either cut Herald of Torment or Mardu Strikeleader if I were cutting a similar card.
Release like this just makes me wonder if one day, classic 360-450-540 powered cube could get larger and still keep about the same powerlevel as they are right now. And FWIW, this is not the only new card that makes me feel like this. Over the years, Wizards just keeps printing really good stuff. Most of them are creatures though. And to actually inlarge those powered cubes, we'll also need some more powerful noncreature spells. People should keep a eye on that. Days when classical powered cube reach the 540-630-720 bar is closer than we could have initially thought.
IMO, we are already there and have been for a couple years now. That's why it's so important to talk about includes within the context of your meta.
It's not like it was even 5 years ago where there were clearly just X top cards and making a power list generally looked the same no matter how you approached it. Black 3's are especially deep to where you could pretty easily build two completely different 360 lists and have an even power level between the two (just with a different focus in black).
It's really about what you want to support and what your group likes drafting.