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
Ancient Gold Dragon 2
Probably the second best of the cycle after the treasure dragon. Still not exactly playable but certainly very powerful and high impact when it gets going. I might consider this for a Sneak Attack target at least. Not entirely sure why this one gets a whole pile of extra toughness over the others, some lore thing I am unaware of perhaps?
Inspired Tinkering 5
This is very close indeed to Ancestral Recall when you add up all the parts. In practice it is much closer to Ancestral Vision but even so, this is a lot of value for not all that much mana net. It even gives you the potential to burst out something ahead of curve such as an Ugin. Much as I am a big fan of drawing 3 cards for 2 mana the slow clunky nature of this might well rule it out for cube. You have to have a deck that is wanting to play five drops and then that deck has to want to draw more cards at that point in the curve rather than making some game ending dragon. I will certainly test this as what is there to dislike about drawing cards and making treasure? I just don't see it getting enough play to survive.
Prized Statue 5
This is the mana version of Ichor Wellspring. This will have tonnes of combo and synergy support potential. If you are a deck that wants artifacts to sac then this is very much on the watch list. Bursty, cheap, fixing, three artifacts in one card, so many juicy upsides on this. Not something you want without synergies so not there for drafting cubes but a card with a busy future.
Nimblewright Schematic 3
Well this is just a functional reprint of Servo Schematic which did occasion some play as a three in one artifact card on the cheap but I suspect Prized Statue now steals that role leaving this a little lost. A fine card but narrow and ever so fair on the power level.
Navigation Orb 2
Gates like this, not fast enough for ramp in most other settings. High Tide in EDH I guess wants this too!
Underceller Myconid 2
Three bodies in one and a mana dork. Not really sure where this fits in but it is likely to find a home somewhere with all those synergies. Base power is low but not terrible.
Druidic Ritual 1
Cool as this milling Divination is, support cards want to cost less than three and value cards want to be without conditions leaving this with little hope of play.
Druid of the Emerald Grove 5
A three for one with some ramp potential. A bit high up the curve for such things but pretty good considering. Civic Wayfinder is OK filler and this is probably better.
Colossal Badger 1
A bit all over the place. Dig deep might have been a nice mill support card but it needs a target before it mills. It is also hard to get excited about a Craw Wurm on the back-end either, regardless of any Healing Salves you slap on!
Cloakwood Swarmkeeper 6
Likely too narrow for drafting cubes but a dangerous scaling one drop threat. It is instances of token generation rather than number of tokens meaning it is a bit harder to scale up. Even so, being a one drop means it still has masses of power potential and will find itself as a cornerstone in aggro decks able to empower it reliably.
Reckless Barbarian 5
Eye opening card here. Low base power and on the narrow side but quickly able to scale up effectiveness in the right sort of deck, be that stormy or tribal or ramp. I am more used to using non-creature burst mana in red and so don't know exactly where this will fit in. It is too useful and cheap and direct not to see play. I am not expecting it to work out in the drafting cube however.
Zhentarim Bandit 2
Too vulnerable and low power these days but a cute little card I would at least like to play with.
Myrkul's Edict 2
With the number of tokens kicking about in cube Edicts have not been good for a while. Really we need one that hits non-token stuff, or indeed this one if it rolls 20 every time... I might play this over Chainers or Diabolic, but probably not, but really I am just not playing any of them.
Mold Folk 4
Carrion Feeder reigned in on the broken side of things and compensated with some bonus fluff. This is an OK support card and will see some play but it will never be a top choice.
Guildsworn Prowler 6
Not really threatening enough as an attacker, obviously not optimal as a blocker (although fine), leaving you with a card you mostly want to use in a sac deck which in turn means you probably just want a dork that makes more stuff to sac directly rather than helping you draw into it and thus need to play it as well. A fine card but just lacking punch. Ultimately a card that is filler.
Gray Slaad 1
Back end just isn't worth having and the adventure doesn't really do all that much. Best thing about this is that it is a mill card and a creature in the bin, sadly if used to mill you then need to make the dork if you want to get it in the bin ever and no one enjoys paying 3 mana for 1 toughness and no EtB or on death triggers...
Winter Eladrin 4
Man-o'-War is a fine card and so is this. It can't loop itself but so what outside of Aluren decks? It has some useful types and so is likely to get some play. Barrin rather reset the bar for these bouncers and Barrin is not a great cube card.
Sword Coast Serpent 3
Brazen Borrower this is not. A seven drop sans flash is orders of magnitude less relevant and useful than the faerie. Not that it matters at this point but the bounce is worse here too, all be it not by so much that it renders it useless. Just highlighting lack of redeeming features in a direct comparison... There are at least numerous decks I would rather run this than Winter Eldarin!
Steadfast Unicorn 2
Not powerful by any means but the best of the many cards like this already out there. Eventually this kind of over cost minor team pump will get printed on a 2/1 for W and it will see a bit of play and be fine. On a 1/2 you need to be full tribal or abusing something like a Training Grounds and even then this is filler at best.
Blessed Hyppogriff 6.5
Finally an adventure combat trick that gets the pricing right. This card is primarily a counter to a removal spell but it is one that offers to either not be dead or some extra value. And while that value/lack of deadness isn't great it is actually offering some threat at a fairly low cost considering. It is very low powered but it is quite suitable for the kinds of deck that are into a one mana protect a dork card. This all lines up in the ways you want it to and so despite the fairly poor power level this has a genuine shot at making it in the cube. There are just not many combat trick / protect spells that are viable so those that crop up and are tend to get play and impress.