Urabrask, Heretic Praetor 5
While quite powerful this just isn't really competing with either the five drop threats in red, or the effects that get you extra cards to play each turn. Urabrask is a little slow and vulnerable to use for value and a little low on tempo and evasion as a threat. The disruption aspect can be fairly brutal against control decks but they are at fairly low risk of having to endure it. Overall it probably blanks about 30% of draws while also reducing the quality of plays made while active by a somewhat arbitrary 10% or so. All fine but not quite enough, and that is in the matchup where it has most value. Certainly this new Urabrask is powerful enough to seem fine in most cubes, he just isn't going to be an optimal inclusion if you are maximising for power. We all like extra cards though so no judgement on those who want to put this in a cube maxing for power.
Getaway Car 2
A cute means to bounce stuff of your own you want to replay for value however not all that powerful by itself and not all that reliable as an ongoing tool. Needing to get into combat makes it vulnerable and as a mere 4/3 it is likely to be answered or traded off if needs be. Crystal Shard has long since been a played cube card, flicker is the new self bounce. Self bounce is just way too poor in tempo to be a good way to get value.
Ob Nixilis, the Adversary 7
Love the design and range here. Just as a fine 3 drop walker Ob is cube worthy but it certainly isn't bomb like. The power is more in the fact that getting a half decent three drop walker down can just snowball a game. It is the casualty ability that turns Ob from fine to quite exciting. Two walkers both gaining a loyalty and nugging or draining for two is threatening to say the least. Devil tokens are a pain to attack into and do a pretty good job of protecting the walkers. You can even fire off the ultimate immediately should you sac something suitably big! Commonly you will be sacrificing a one power dork and so that Ob will +1 while the other non-token one will +1 or -2 first as appropriate for defending them. Overall this probably compares to Daretti, Ingenious Iconoclast fairly closely. Daretti has good removal making it more disruptive, more generally playable, and a superior control card. Ob however is rather better offensively and is a much more pressing threat itself. Both are improved by having good things out and ready to sacrifice for the turn you make them. Both are three mana Rakdos walkers and will compete for space in cubes but I am imagining both have sufficient power to last along side one another even if Daretti is probably the more powerful on average of the two. Ob is a cheap threat that provides options, range, good pressure, and significant board presence. Despite looking like he is most suited to a more aggressive list I think he will perform well in most types of cube deck and once you have high power and high playability it rather stops mattering what other similar cards are better.
Cut of the Profits 0
Very clunky and not exactly powerful either. There are too many black cards that pay life to draw cards in some way that I would play over this to name them. The OK top end on this might make it OK in EDH but cube and 1v1 play looks to the low end first and that is all but absent on Cut the Profits.
Mysterious Limousine 6
I am not normally a fan of the Banisher Priest style white removal dorks. This however interests me rather more. Being a vehicle makes it far more robust in the face of removal. Nothing is worse than having your Fairgrounds Warden Wrathed alongside your team while giving your opponent back their dork. This Limo feels a lot less risky and as such a more appealing removal tool. Being a 4/4 makes it rather more useful in combat that the 2/2 and 1/3 statlines of most previous bodies with this kind of effect. Being a useless body that you don't want to get into combat really just results in it being a drawback and makes you wish you had Oblivion Ring instead. Limo can get a bit more stuck into the fray and put the body to some actual use. The final thing I like about the Limo is that you can swap around the target. This gives you lots of flexibility and control. It means you can make this onto an empty board and not feel like you are wasting a removal spell. It means you can hit something limp and then still be able to handle a big scary thing later down the line. It allows you to chain murder a token dork every turn. The last, but certainly not least, use for this I can see is as a flicker tool on your own dorks to power out some EtB triggers. Drop the Limo, exile your own Priest of Ancient Law. If they remove the Limo then you get a card, if not you can still get your card and flicker out something else. This card offers some reasonable tempo and a whole load of options. It does need to perform well however as it is a five mana sorcery speed non-permanent removal spell at heart and being a vanilla 4/4 vehicle is not an inherently powerful thing either. That rather makes you want to be able to crew it reliably which narrows the card somewhat. The Limo is competing with the likes of Elspeth Conquers Death and so it really does have its work cut out for it. I think it is good but I do not think it is any sort of Glorybringer. I think this winds up being a bit too midrange lacking the reliable crew from control and the lower casting cost desired by aggro lists. With fewer archetypes into this it likely doesn't get enough cube action to last. Things are moving towards midrange being the king in my non-combo cubes at present so this is certainly not without hope.
Nible Larcenist 3
We add blue to the cost of Sin Collector and get flying and the means to hit artifacts. Sure. if you are these colours this is a decent card. A disruptive two for one with reasonable tempo. Too gold for cube where we will have to stick to things like Kitesail Freebooter.
Vivien, on the Hunt 6
Expensive but powerful. You can put dorks into play or find dorks or do both at the same time! There is some value and some tempo and some threat here. It isn't super quick or at all disruptive but it is pretty playable. In a deck with a toolbox of utility dorks the card is great, in a mono green deck it is perhaps a bit to much more of the same. I don't think it will last in cube just because six drops in green seem to do a really good job of ending the game sharpish and as such will be chosen over this most of the time. You can get toned down versions of this sort of "find dorks or make mid sized vanilla tokens" all over the place for less than that hefty six mana price tag.
Tramway Station etc 2
Far too low powered for most cubes but great for pauper and budget cubes. Lands that cash in for cards are amazing flood protection and are one of the simplest fixes to the main issue with the design of MtG. With there presently being so few lands that do this and with most of them being painful inclusions to lists I can actually see these creeping in to some places you might not expect. EDH for sure but perhaps even the likes of pioneer. Nice to see more mindful card design that helps to improve the game overall. I hope to see more lands like this in future sets that push the power level a little harder.
Rumor Gatherer 5
This rather excites me as it would seem any card draw or quality in white does. Much as I desperately want this to be good enough I doubt it is. You need this to live to be good and then you need to have follow up. The body is pretty useless and easy to kill. Play this early and you concede tempo and likely get it answered. Play it late and it is having little impact on the board and it will be insufficiently fuelled from hand. With enough cards that trigger the draw all by themselves like Blade Splicer and Elspeth, Sun's Nemesis I can see this working somewhat it but at that point the card is just too narrow.
An Offer You Can't Refuse 8.5
This looks like one of the biggest cards in the set. This will see a lot of play in a lot of formats. This is a one mana hard counter with a very broad target range. Spell Pierce is one of the best counters in the game and while this isn't better than Pierce directly it is certainly a lot better in a number of situations and matchups. Value wise An Offer You Can't Refuse is worse than Negate which trades a net of two mana and one card for their card while this is a net of three mana for the exchange. Further to that giving away of treasure will allow them to make burst plays, it might help fix their colours, it might even empower artifact or sacrifice triggers. Giving away two treasure is absolutely not trivial. But then neither is giving away a land with Path to Exile and that has been premium disruption since it was first printed. Much like other cards that concede some mana to the opponent An Offer You Can't Refuse gets better as the game goes on as the relative power of two mana decreases and the uses for mana in general dwindle. Spell Pierce, which looks to be the closest card to this in design, scales in exactly the opposite way. If An Offer You Can't Refuse is equivalent to the likes of Path to Exile then we can compare Spell Pierce to being like Fatal Push, Disfigure, or Flame Slash. In terms of play pattern and style I actually think the best comparison for An Offer You Can't Refuse is Force of Negation. Both have the ability to Negate for less than two mana and both have a cost for doing so. Both are also able to mitigate that cost as the game goes on. Force of Negation is outstanding and so I suspect will this be. In places like modern the strength of this card will be in the ability to trade 1 for 1 with things from the outset. In cube the strength will also lie in being able to counter big plays like planeswalkers for just one mana and still getting that tempo win. I am getting those large tempo gains not just from my net gain of mana on your 4+ drops that I hit with An Offer You Can't Refuse but also from the ability I have to safely deploy something else on my turn with only one mana left up. Turn five, make Elspeth Replendent, use the -3 to go and find and uptapped blue source and then An Offer You Can't Refuse their next turns play with it is potentially going to be a thing in standard. That is quite the swing. It certainly sounds like a big old swing in cube.
You can even use An Offer You Can't Refuse as a semi Ritual by hitting your own stuff! Niche to say the least but not out of the question, especially in a deck packing cards with storm. Seems a bit extreme but you can use An Offer You Can't Refuse to ramp out something like Jace TMS on turn two if you counter your own Gitaxian Probe on turn one. Seems dodgy but is at least super cool. Anyway, this card is versatile which is nice, but more importantly it is just plain old powerful. A three mana counter is fine and those that are less than that tend to be too powerful for most settings. An Offer You Can't Refuse kind of gets the best of both worlds in the way Unwind really didn't. On the face of it Unwind is a hard counter for zero mana but in reality having to keep up three mana to have it be active made it unwieldy and terrible. All the reasons that Unwind was awful despite seeming like a net zero mana one for one Negate make An Offer You Can't Refuse likely better than Negate despite the net mana cost being three. That low up front cost to have it active is just so important for counter magic.
Eek. This is a very bad removal spell. Unplayable so in basically all formats. Edict effects are best against one dork and Incriminate is a dead card against only one dork. This basically says target player sacrifices their 2nd best creature which roughly translates to fail to answer the problem. This is one of those sneaky cards that tries to pretend that it could be good but General Ackbar knows.
Light 'Em Up 1
Close to good but not. The baseline is just too limp. This could be instant and interesting, 3 damage and sufficiently powerful, able to go face thus offering decent reach, or perhaps even just have casualty one instead of two thus offering a greater range and lower cost of fuel. But it doesn't and so it is just a very underpowered removal spell that you can infrequently do some cool things with. Shame but reasonable design choices as any of the suggestions I have given to make it cube viable would make it pretty oppressive in booster draft.
Courier's Briefcase 2
Cute card but not enough returns to be a consideration. The draw three is not something easily pulled off on top of being very late game. The rest of the card simply isn't worth the investment. If Prosperous Innkeeper can't make it in cube this certainly can't.