OK, learning this thing slowly. Please let me know of any issues with images. It isn't the same at all at this end so I suspect that will translate to readers on any platform.
Szat's Will 1
This is a lot of tokens but at a high price and with very little reliability. Edict backup is nice too but it is hardly cost efficient either at five. I can't see this being viable without abuses much as I love the idea of making a tonne of fodder. Obviously nice if you get both modes but that is not something you can consider in formats without commanders. I can imagine a selection of house rules that could apply to cards that reference the commander in normal cube magic such as a companion counting or a designated in-deck legend or some such thing. That would make cards like this a lot more interesting but it is hardly like we need more cards at present. This still wouldn't get that much action in my cube even if it always triggered both modes. The Eldest Reborn is generally more powerful as far as overpriced edict effects go.
Tevesh Szat, Doom of Fools 5
This is a sac decks wet dream but it comes at a high price. Tevesh just makes chumps and sacs chumps to draw cards. Two loyalty and two 0/1 chumps a turn is good return when you have uses for the tokens beyond protective chumps. If you fail to have that sort of aristocrat deck Tevesh is just a relatively slow draw engine. He should net you over a card a turn but it will not be reliable or consistent. At five mana too I would like a bit more utility or threat. I like Tevesh a lot but it seems a little narrow and fair to really do all that well in cube. One worthy of some testing at least. Lacking a relevant ultimate in non-commander formats really takes the danger away from this card and makes it more of a supporting tool and not the game ender you want your five drops to be.
Nymris, Oona's Trickster 1
This just seems like a lot of mana for a really lame body that needs further support just to then be a value engine. Too un threatening for a five drop.
Sphinx of the Second Sun 6
Wilderness Reclamation, Paradox Haze and Coercive Portal all rolled into this 6/6 flier. This is a bit of a slow burner as far as an 8 drop goes but it will start to dominate the game pretty quickly. The power level here is pretty phenomenal. It is effectively 0 mana once cast as well making it generally pretty safe. You can get blown out with counterspells or instant removal leaving you tapped down and not getting that card back right away but other than that it is a free play once you get to 8 mana. No easy feat but still done most of the time by slower cube decks. It is as close to an EtB Time Walk as you can print without combo abuses which is impressive design and results in a refreshingly new feeling card. Certainly worth testing. Given it has a chance in cube it is going to be a total bomb in commander...
Ghost of Ramirez DePietro 2
This needs a lot of setup and support. There are better ways to get value out of a dork than this, not to mention better dorks. It does at least have two good tribes in which it might find a home.
Lieasa, Shroud of Dusk 4
Baneslayer Angel meets Eidolon of the Great Revel. This is good in commander and remains OK in cube play. This would be a decent top end dork for an aggro deck that pressures life totals. That however isn't really what Orzhov does in my cube at present. Just a little narrow and top heavy to quite make the cut but pretty close.
Seraphic Greatsword 0
Awkwardly bad, do nothing much when ahead and make one Angel token with your wildly overcost Vulshock Morningstar when behind somehow in your aggro white deck. Seems unplayable in 1v1.
Phyrexian Triniform 1
Too pricey and lacking in evasion to be that exciting of a threat. As something to Weld in and out of play or Sneak Attack in for value this has some things going for it. Probably not enough to outclass the cards already used in these ways however. The encore is a big deal in multiplayer but is extremely pricy to the point of near irrelevance in heads up play. Trample would have gone a long way here.
Mealstrom Colossus 1
Cascade on a big and easily cast-with-colourless-mana card is interesting at least, even if it doesn't have much obvious use. With things like Metalworker and Workshop etc this is easy to flop out although it likely hits you a cheap mana rock and not the Karn you were hoping for...
Bladegriff Prototype 1
In decks with Lightning Greaves and other means to protect and give haste in a broadly colourless sort of setting this has some mild hope. Mostly it is a 5 drop you get Shocked and are sad about.
Rebbec, Architect of Ascension 1
Mostly just a less reliable Leonin Abunas however it does help make artifact creatures unblockable so there is that going for it. In white affinity or Tempered Steel lists this has a bit of hope in that capacity. Thing is those decks don't have a huge spread of CMC cards so it is only helping against smaller dorks. Still good but pretty narrow, I'm not a fan of 4 mana non artifacts in my affinity builds either.
Keskit, the Flesh Sculptor 2
Very nice effect but the cost to use is extreme. You really need some impressive ways to generate token chaff, probably the 0/1 kind, recursive things like Bloodghast, and artifact tokens like food. If you can make that happen then this is going to be pretty wild, if not then leave this on the shelf. It is almost never going to do more for you than a Priest of the Forgotten Gods either being slower and not affecting the board in any positive way for you.
Profane Transfusion 1
Big and fun but situational in addition to being somewhat underwhelming. One mana cards like Death's Shadow are rather better things to do when self harming. Almost anything else is a better strategy than this for stopping a beatdown. The token is pretty random and unexciting. The 8/8 token from Crush of Tentacles has won like a single game ever despite being summoned hundreds of times in my cube. At least this Transfusion is pretty interesting and fun in EDH which is after all where it is designed for.
Eyeblight Cullers 0
Lots of tokens but conditional and really rather too far up the curve for a support card. Weaponcraft Enthusiast is the thing to use if you are considering this.
Ikra Shidiqi, The Usurper 0
A reprint so dull I nearly forgot it existed already. Don't play this in cube. A more efficient and accurate review the second time round I suspect.
Opposition Agent 6
A very powerful effect for sure although outside of combo cubes this is mostly just stealing sac land targets. Don't get me wrong, that is game breakingly powerful, the old 3/2 for 3 Rampant Growth Stone Rain... it is just that it is a 3/2 flash most of the time. Do you sit on your card and hope they have a sac land, do you play out your low value 3/2 chump? Neither are good options and that is mostly what you will be facing. Obviously the more tutor cards you are running in cube the more playable this looks. It is sufficiently powerful that it won't take much in the way of search cards to make it good in any given cube, it will just always be quite the polar card. Either back breaking or poor. In settings where you can build around it with delights such as Scheming Symmetry and Maleren the Mornsong then you have a bomb on your hands but such things are going to be a little tricky for singleton and a little too cute and slow for legacy or vintage.