Blue Sun's Twilight 7
Dominate with some tweaks. The mana reduction being the main one which turns a really clunky card into one with some potential game to it. This steals a token at 2 which is somewhat relevant in cube these days. I would say BST is good in the early game, a little underpowered and situational in the mid game and pretty nuts in the late game. When, at 7 mana, you can not only have this as a Control Magic but also a Clone it is all a bit swingy. That late game power answer on top of a fairly versatile and swingy card in the lead up to that is grand. It isn't going to do much if you are getting curved on but that isn't the most common way to lose in cube by a long shot, even my midrangy one. It is far more common for little awkward or snowbally cards to do critical damage or for a swarm of one and two drops to happen. In those cases this is more reasonable protection, arguably better than Control Magic simply by being something you can flop out at two and three mana and still stand to get a tempo two for one. I do not inherently like this sort of card but I have to concede that this is absolutely one of the most viable contenders for cube of cards like this. One could argue it is a fixed Control Magic. It doesn't have that foolish back and forth swing of being able to take their best on curve dork and just win off the back of that if they can't answer it. Equally it avoids being too narrow like Threads of Disloyalty. It will be interesting to see how this performs, I don't like it but objectively I see this panning out. More for being viable removal in blue than directly being a great card or anything. On a little side note there seems to be a new glut of cards that scale well into the late game like Crackle with Power. Things that you include in your deck as early plays, such as the new prototype cards, that when you peel them in the late game they offer substantially more power. These turn out to be really valuable in cube at present with low curve and high tempo stuff being critical to have in abundance, which in turn makes proper top end game winners and cards that can push through a win being hard to find and include. Cards like this let you have something to get playing early but allow you to win pretty hard if you can make it late with them.
Karumonix, the Rat King 2.5
Sure, a tribal rat man. Mostly a commander card but I will play this in a rat deck, perhaps even the odd poison and ninja decks. Build around only although sufficiently reasonable as a commander to do a lot of work empowering an otherwise very limp tribe.
Green Sun's Twilight 6
Fascinating. This starts life as a shonky cycler, moves through a middling Divination patch and then winds up looking like a Tooth and Nail! In terms of hit rate you want a deck that is 50% dorks and 50% lands. That isn't a million miles off what heavy/mono green decks look like in my cube presently although it is rather closer to 40% of each and 20% stuff that is going to be a miss. Am I ever cycling this on turn one for G? Yes, probably if I am light on lands, but that chance of wiffing does make that a pretty dodgy play. You are already some statistical percentage towards a mulligan if that is your line so such hands are automatically things you are more likely to ditch. How about trying to get that Night's Whisper feel? Even with exactly 50/50 mix of lands and dorks in deck firing this off at X=1 is only resulting in hitting both fractionally above 50% of the time. In reality it will be under a third of the time you double hit, with a good 4% chance to wiff all together also helping to lower the average draw. Not something you are going to do eagerly but none the less something you will do relatively happily. You do at least get to chose the best dork or the best land when you hit the same type twice! You can even go nuts and increase your odds on hits by playing Dryad Arbor for that double type scaling! Arbor really loves a Green Sun at any time of the day! At X = 2 through 4 we are just looking at reliable card advantage and selection. You still always get a land so the value is less saucy than the card quality but it is all good. It is just a thing you are more than happy doing whenever you have spare mana, the need of setting up, or a lack of other stuff going on. The only time it is really awkward is when you are behind on tempo and have nothing to do (but not 6 or more total mana). Then you have to make the awkward call of only spending a bit on X in the hope you will find and hit a dork you can still play that turn or going full X and taking the tempo hit. Gross, but pretty interesting!
Once you hit six mana this card gets really good as it is likely value and selection with minimal tempo costs and potentially tempo gains. Find a six drop dork or bigger and you are up on mana. Otherwise just get a lot of choice on which dork you want as well as a free land for not much cost at all. I guess as the land you get is untapped you can technically make tempo gains from a mere five drop but that is trickier. All in all I think this is a great card. It has a very wide range of what it is actually doing for you but they are all things that are pretty appropriate for whatever stage of the game you are at. I really like it, it is a touch clunky and risky but it is super interesting. Normally I hate cards that dig into big dorks and play them for you as I would just much rather have another fatty in my deck. This bypasses that downside by being able to mimic a cycler, or Divination, or Night's Whisper early and thus manages to increase your top end threat density while also improving your low end consistency rather than reducing your top end threat density as cards like Tooth and Nail necessarily do. I want this card to succeed in cube. I love me card quality and card draw. This is clunky and risky and that is scary but I am hopeful it has enough range and power to offset that. In reality the viabiltiy of this card comes down to the % of misses you have in your green cards and decks in your cube meta. Much below 80% targets in a deck and I am going off this fairly fast. I think therefor for most cubes this will not be worth it. For mine right now I have some hope but I cannot envisage it surviving much in the way of meta changes. A seasonal sort of cube card!
Kaito, Dancing Shadow 5
I like this guy but is he good? He does 3 really good planeswalker things. 0 to draw a card is clean and solid. The +1 is a reliable utility tool that can force through attackers to enable the passive or simply work defensive duty. Flopping a walker and negating their attacker is a time old tradition among most decent planeswalkers. Just poising to untap and offer utility backed up and protected by open mana! The -2 offers some very significant board development to help stabilize a game. Often walkers suck because when you play them late they are just ignored. The -2 really helps make a late Kaito do work recovering a game. Some life gain, a blocker, and the potential to trade up are all great. It is likely why Kaito can't start with 4 loyalty as back to back -2 would put a lot of games out of reach. Sadly it is that low loyalty that makes me think this is not going to cut it in cube. I fear this is too easily burned or sniped out with evasive and hasting dorks that too little value will be had from him. The passive is great but it is narrow and win more. If you are full of Steel Raven then it is super juicy but in cube it will not enjoy that kind of luxury. Yes, the +1 supports the passive but the -2 doesn't really. Sure, the passive scales nicely with your EtB dorks but again, this is super win more. Mostly this is a card is just a little risky. If leaning on the token you get blown out by so many things. Equally, if you are leaning on the +1 to keep Kaito safe a single spot removal spell will put you behind in tempo with no card advantage to show for it. I do like this card but it feels like a really weak version of the three drop Kaito. This is more fun for sure and will be cooler in EDH but it does not have the look of a cube card. Fine, but not good.
Conduit of Worlds 6
This is one of those cards that rings danger alarm bells. I think it is just about balanced, or counter-balanced, to the point where it isn't going to be oppressive in cube. It reminds me somewhat of Wilderness Reclamation but as a value source rather than a mana source. This is unlimited action but only in a world where you are on curve, or have mana sinks, or abundant permanent cards with flash. If your deck is just a pile of normal stuff in a normal curve the one card per turn limit is going to really crimp the power of this thing. Just making a 3 drop on turn 8 when everyone has at least 6 mana sounds like a losing play. You need to be doing more than that and that is what makes Conduit a little narrower than it might appear. It has some real vibes of Lurrus in that you need specific kinds of cards that let you play around the drawback effectively. This is no real issue in cube with plenty of lands doing the job by themselves with cards a plenty also happy to drink all your excess mana. You can play a sensibly curved deck with Crucible and still have it represent all the gas. So, is unlimited gas worth it for four mana? In a world not so long ago that would be a firm yes but in this age where tempo dominates and you can get plenty of gas from cards that are not tempo negative such as Toskie or The Great Henge or just a simple Tireless Tracker I am not so sure. Certainly going to give this a test as it is quite the big ticket item but I can see it getting cut the next time I trim the fat (longer than a test but likely just before the next set drops).
The Eternal Wanderer 7
Six is a big old ask from any cube card in 2023 and for planeswalkers it is basically terminal. Sun's Champion is my only remaining walker over five mana (other than Ugin the Spirit Dragon) and she is feeling tired and limp these days. This does have 4 immediately useful abilities. The passive makes it hard to attack profitably or deal with in combat quickly, the latter is a big part of what keeps walkers balanced so this will do pretty well against go wide decks and those without removal that directly targets walkers. The +1 flicker is something I have wanted to see on a mono white walker for a while but on a card with the right mana cost to be widely usable as opposed to being far too late to the party! I want a three drop with flicker not a six drop. The 0 is fairly meaty but it is slow. My gut is that it is bad on a six mana walker but that is because other walkers do not have the passive that The Eternal Wanderer enjoys, with the limitation on being attacked I think the 0 is probably decent enough. Some OK safety and some reasonable pressure with decent scaling potential. Really this is all about the -4 which is a Wrath of sorts. A very good one if they have bad dorks and good dorks. A very poor one if they just have the one fatty. I am not a big fan of the polar situational Wrath but on an otherwise reasonably safe and rounded walker I am OK with it. While the passive does not work smoothly with the -4 as both leave you vulnerable to one big threat the +1 does at least calm that problem and buy time to change the game state. I certainly do not think this is a bomb but it does look at the very least to be a strong challenge at Sun's Champion, which is the bar to clear for six mana walkers in my cube.
Dragonwing Glider 7
Big fan of this card. It is basically a red Maul of the Skyclaves. You pay 2 more mana to deploy this and one more to re-equip it but you get a living weapon style effect of a 2/2 to slap under it. What I like about Glider is that it offers a really good degree of reach. Have this in play long enough and it should be able to close the game. It turns anything into a relevant threat pretty much and it does this without being a weak play on curve or even just on the turn you make it. It hits hard and fast and demands an answer. It is not a bomb by any means with 4 power flying haste dorks with upside in red for days. The perks here are in safety of threat. You are playing this to kill people which it will do if not answered and in doing so it will typically generate some value. Either you get a free 2/2 token or you get to keep the threatening equipment. Power wise this is nothing to rock the boat but suitability wise I think this is one of the better options. It is especially brutal with Stoneforge Mystic and is probably the most exciting thing you can pair with it in cube with the classic Batterskull being a bit weak by itself and a defensively leaning card. This is a nice proactive equipment you are happy to play for 3RR when you can't pay 1W for it! Living weapon is the fix to equipments allowing you to play more than one or two in your 40 card deck. For Mirrodin! is a bit of a mouthful as far as key words go but it is a welcome return in as far as mechanics go.