0 - unplayable in 40 card singleton
1 - effectively unplayable
2 - has low tier constructed decks it might go in
3 - has mid tier constructed decks it does go in
4 - pretty powerful stuff with several potential homes, able to perform well in lower powered cubes
5 - powerful stuff that is either just too narrow or has too many superior alternatives
6 - fringe cube worthy
7 - cube worthy
8 - cube staple
9 - unpowered cube bomb
10 - powered cube bomb
Broker's Veteran 1
If this were on EtB effect rather than a dies one I would be rather more interested. As it stands this is too low power and too unreliable to play. I do like cheap shield stuff though, I like this way more than I should!
Riveteer's Ascendancy 3
Quite powerful but the dreaded double narrow. In 40 card lists even the constructed decks doing this kind of things are probably not able to find space for this fun-times fluff card. I do like this a lot, the grinding power complete with delightful synergy this offers should win a load of games and in a cool way. It is just not the kind of card you can put in traditional cubes as is very much the mantra of this set so far.
Brass Knuckles 0
This is just bad. Bad as a buff and bad as a pile of artifacts/equipment. It has very little use and pathetic power level.
Night Clubber 7
Plague Mare was pretty good in cube and only really lost its spot to Plague Engineer rather than for being bad itself. Plague Mare was a little narrow but useful and swingy. It was never dead and stole many games all by itself early in proceedings. Night Clubber is simply a much much better Plague Mare and may be powerful enough to exist alongside Engineer and Massacre Girl. The Blitz is quite a big deal giving you good options to take over the questionable value of a 2/2 body, regardless of how able white creatures are to block said body... Drawing a card is low tempo but very solid indeed on removal. Kill something and draw a card is hard to get at three or less mana. Kill a couple of things with a card? That costs a awful lot of mana! Clubber also offers some extra planeswalker control. Clear out some gribblies and toss two extra damage onto he attack will generally answer an early walker pretty efficiently if things were close. You can also use Clubber effectively in a sac deck where the blitz mechanic sits nicely indeed. Cards like this are a big part of why my cube has taken a big swing towards the midrange, you simply cannot afford to toss out a bunch of weenie dorks and hope to get there with them before the powerful answers are online. If you invest two or more cards and three or more mana by turn three in things Clubber answers then you will lose to a Clubber almost all the time. A bit like the old Arc Trail. That is the kind of ceiling cards dream of and with a fairly solid floor it is hard to go too wrong. Overall this card seems to have it all. It is not overly powerful but the suitability, range, and versatility should see it become fairly well played.
Riveteers Requisitioner 4
I obviously love this card but I fear it probably isn't powerful enough. As a two drop 3/1 beater is OK on turn two but pretty limited. Later in the game such things get very little done. No timing certainty on the treasure back makes that aspect of the card also unimpressive. Without the blitz option I am playing Wily Goblin (or any half decent two drop beater) over this. Much as I like the blitz it is all a bit at odds to quite get there. Early is when treasure is best however early spending three mana to deal three damage at your opponent's discretion is pretty inefficient and poor tempo. I will still have to try this out to make sure as any card that draws a card and makes a treasure needs scrutiny. Seems unlikely but not impossible.
Torch Breath 0
Nope, this is not the sideboard card for cube. Red has Pyroblast and the like, this can go sit in the corner.
Citizen's Crowbar 7
Well this takes a big old dump on Ancestral Blade. Sure, Blade is one less to equip but that is all it has going for it. Both otherwise cost the same and effect the board equally however Crowbar offers a bargain Disenchant into the mix. This isn't broken, it isn't even all that powerful, it is a slow 3 mana disenchant that gives you a 1/1 or it is a Grisly Bear. What this is is versatile. It is option dense and that is what white needs most. It is a proactive threat and it is removal and is thus all the things you want wrapped up in one card. It can also give you that ability to edge combat in your favour or speed up a clock by dumping it on your one evasive dork. The worst thing about the card is the need to tap the dork equipped to it. This means it is mostly offline when used offensively and more significantly, on the turn you make it. To Disenchant right away it is downgraded to sorcery speed and needs you to have five mana and another dork without summoning sickness you can slap it on and tap. That is a comically bad rate when you can instant Disenchant with upside in multiple colours for two or less. I like this more than Reclamation Sage although it is less powerful. This will make up for that by being proactive and by being a crap Leonin Scimitar when required. White also needs the utility more than green does.
Whack 1
Doubtful this ever gets play. Being sorcery just makes this a lot less interesting as a removal tool regardless of cost. It is not like there are not viable instant speed removal spells of this power level or that cost one mana.
Slip Out the Back 4
This just isn't doing enough to be worth a card. It is a blue Snakeskin Veil but blue has counter magic and not many dorks worth saving. You can use this on their stuff but you don't really want to. Overly narrow and conditional card. I might look at this in the kind of place of Dive Down in some blue tempo lists but I think that is the only place I like this.
Boon of Safety 4
I do rather like this one but I think that is probably just true of every one mana card with scry on it... Sheltering Light and Gods Willing are very similar cards to this and neither see cube play. They are fine they are just too conditional for a limited setting. Boon of Safety is of a decent power level and does nice useful things and will get play as a result, just not very much of that will be in cube like settings. The thing I like most about this is that you can use this proactively just so long as you have a dork, you don't need to wait until the perfect moment to fizzle a spell or win a combat. This facet of the card works nicely with the scry meaning that if you are relying on your draw you can pop this cheaply and really help yourself out without losing too much of the value of the card. It is minor when compared to similar cards but minor things on one mana cards are rather amplified into often significant differences.
Halo Scarab 3
Pretty terrible to cast but a nice thing to incidentally put in the bin. This can fix and it can give a bit of burst and it has nice general utility with artifacts. You really do need a lot of mill and looting for this to get good and of the decks that do such things in sufficient quantities I cannot see where this fits in. Very much one to keep an eye on though.
Endless Detour 4
Curious spell. Part Memory Lapse and part Temporal Spring with a sneaky side of Noxious Revival should you be desperate for something. Certainly this is a versatile disruption tool. What it isn't is removal. Unexpectedly Absent has been falling out of favour for this reason. The card is nice but you only have so much space, every card that is not a threat or an answer (or a mana source) really needs to go above and beyond to justify itself in a cube setting. Absent does not do this, it is just fine and as such it is getting over shadowed by cards that actually remove things more permanently. Further to this Detour lacks the ceiling of cards like Absemt, Temporal Spring and Memory Lapse. Basically when they hit a card that is situationally good or deny a much needed draw they are brutal. They give the feeling of going better than one for one. Detour gives the option to put to top or bottom and it gives it to the opponent ensuring they do not have to redraw something poor. I do like this card but it would be a stretch to include in cube as a two colour card, at three it isn't there for me by quite a way. In 60 or 100 card decks where you can much more afford stop gap cards this should see rather more love as it is incredibly broad. Any deck wishing to take the game long is into what this is doing. It is undoubtedly a good card, just not well suited to cube.