This is a great idea! It has a similar goal as a project I envisioned some years ago called Casual Cube Constructed (C to the third power), where I would design 40-card Highlander decks with a theme too niche to fit into my main cube. I had a ton of ideas but only managed to build two actual decks, which I then finetuned to be played against each other, ending up with basically Duel Decks (like the WotC product). Here are the lists, I encourage anyone to try them, the gameplay was excellent!
Pretty good on turn 1 with Mishra's Workshop, but then again most artifacts are. It's indeed worse than Stonecoil Serpent, but that card is legit great. It's also a creature with CMC 3 or less with lategame power, which I like for my Vial/Company creations. Might give it a real chance!
Seems really good to me. Excellent defensive ability, great card advantage potential, cool third ability. Likely the second-best Green 5CC Planeswalker after the complete monstrosity that is Nissa, Who Shakes the World. Seriously, have you played with that card?! I also still really like Nissa, Worldwaker and Vivien Reid (who has turned out waaay better than I expected), so likely I'll play these four in my larger cube, leaving Garruk, Primal Hunter out.
This card is bonkers. There's already some great Cube cards that incentivise you emptying your hand as fast as possible (Hazoret, Wheel, Scroll) and this fits great alongside them. I've enjoyed Heir of Falkenrath as a card that's decent in both aggro and reanimator, and while this is a turn slower for reanimator, it's actually better there because it's a threat that requires answering by itself! 7/6 is just absurd for so little mana, a token generator on the opposing end will happen often but even then the WCS isn't close to something like Master of the Feast. Discarding yourself isn't nearly as big a deal as letting the opponent draw cards. Possibly the perfect Black 3-drop.
Definitely the first four, I also like Viscera Seer and don't know if Cruel Celebrant is really necessary. Black/Red is the best combination for an Aristocrats deck and in my Cube is so consistent that if you just take Black/Red duals first you often end up with a strong version. The main advantage for this strategy is that the cards are individually not so powerful, so you get them much later than the key pieces for other archetypes. One of my favorite decks in Cube.
Edit: Forgot about Falkenrath Aristocrat, mostly because it's so bonkers I assumed it was already in most Cubes (similar to Greater Gargadon)! This is one of the best Rakdos cards in general, I'll run it in any Rakdos deck that has enough creatures but it's particularly insane in this shell.
FWIW, this is the tier list I came up with over many years of Cubing:
GOD Tier
1. Black Lotus
2. Sol Ring
3. Ancestral Recall
4. Time Walk
5. Mox Sapphire/Pearl/Jet/Ruby/Emerald
6. Mana Crypt
7. Library of Alexandria
8. Mind Twist
9. Mana Drain
The cards on this list are not only brutally powerful, but their power is not deck dependent. They will consistently win games regardless of matchup or difference in skill level, because they are pretty much impossible to defend against. For balance reasons you should probably run either all or none of them, my cube has none.
Combo
1. Time Vault
This is the one combo card that I think is far too good for an unpowered list.
Extreme power/variance
1. Channel
2. Show and Tell
3. Eureka
4. Bribery
5. Jace, Memory Adept
These cards I would also exclude from a non-powered list, the combination of power and variance is more suited for powered.
Besides these (and UN-cards/Conspiracies which I didn't include because of my lack of experience with them), I think pretty much anything is fair game given appropriate balance in the Cube.
Powerful and flexible answers like this card improve basically any Cube. For that same reason cutting Maelstrom Pulse seems like insanity to me. If you don't have room in Golgari, this is a card worth cutting a black, green, colorless or other Guild card for.
I actually really like Staff of Nin, it's way more clean and elegant than this card... which sure has a lot of text. I like build-around cards but this one also doesn't excite me in that way, unlike say Birthing Pod or Oath of Druids.
This is a cool ability that will not cut it in Cube, I think. I also hate giving away information (I like instants) and thusly suspect I wouldn't really enjoy playing with this card. Doesn't come close in power level to either Grave Titan or Massacre Wurm, the latter being one of the more underrated Cube cards.
Indestructible sadly doesn't save it from many of the things I'm afraid of when I reanimate a fattie without an ETB trigger. Despite the keyword soup not a particularly impressive creature given the 8CC, and it doesn't work with many alternate fatty-cheat cards like Tinker or Natural Order.
The fact that black 5-drops aren't great is very compensated by the red 5-drops being amazing. As fun as this card could be, give me Siege-Gang/Thundermaw/Kiki-Jiki/Conscripts/Glorybringer/Sarkhan any day. There's also plenty of Rakdos cards that are more critical to the decks I draft than another expensive planeswalker.
This card (while fun) doesn't seem that great to me. I spent forever trying to make Pattern to Rebirth happen in my Cube and it didn't really pan out, despite it being monocolor, splashable and having an arguably stronger effect.
Temur Energy: https://deckstats.net/decks/1121/926989-casual-cube-constructed-temur-/en
Esper Dragons: https://deckstats.net/decks/1121/925647-casual-cube-constructed-esper-/en
I wrote other ideas for decks like these down, and I'm sure some or all of them could also work in a Jumpstart setting:
Turboland
Enchantress
Eldrazi
Ninjas
Goblins
Soul Sisters
Threshold
Delirium
Devotion (any color really)
Morphs
Nic Fit Rector
Death's Shadow
Domain
Taking Turns
Turbofog
Mardu Warriors
Bant Spirits
...
The possibilities are endless!
Edit: Forgot about Falkenrath Aristocrat, mostly because it's so bonkers I assumed it was already in most Cubes (similar to Greater Gargadon)! This is one of the best Rakdos cards in general, I'll run it in any Rakdos deck that has enough creatures but it's particularly insane in this shell.
GOD Tier
1. Black Lotus
2. Sol Ring
3. Ancestral Recall
4. Time Walk
5. Mox Sapphire/Pearl/Jet/Ruby/Emerald
6. Mana Crypt
7. Library of Alexandria
8. Mind Twist
9. Mana Drain
The cards on this list are not only brutally powerful, but their power is not deck dependent. They will consistently win games regardless of matchup or difference in skill level, because they are pretty much impossible to defend against. For balance reasons you should probably run either all or none of them, my cube has none.
Combo
1. Time Vault
This is the one combo card that I think is far too good for an unpowered list.
Extreme power/variance
1. Channel
2. Show and Tell
3. Eureka
4. Bribery
5. Jace, Memory Adept
These cards I would also exclude from a non-powered list, the combination of power and variance is more suited for powered.
Besides these (and UN-cards/Conspiracies which I didn't include because of my lack of experience with them), I think pretty much anything is fair game given appropriate balance in the Cube.