Throne of eldraine

Note on Adventure: If you play with adventure cards, you send them on an adventure and they return to you. Unlike the rest of the zones, you each send creatures on their own adventure.

Charming Prince
Two of the modes on Charming Prince are particularly strong for Cubelet and useful.

Brazen Borrower
Petty Theft is a neat tempo play and going on an adventure is your own thing, so the card is at your disposal for the rest of the game.

Murderous Rider
There are better removal spells, but this can be a nice budget inclusion.

Oathsworn Knight
Takes advantage of a player without a creature to get some damage in, otherwise, kind of a lackluster card

Rankle, Master of Pranks
Each player is very powerful as well and flying. If your cubelet is built in a way to handle these factors, then this is a neat inclusion.

Bonecrusher Giant
Fair card to consider. Nothing flashy or overpowered here.

Robber of the Rich
A neat way to catch up when you've fallen behind.

Oakhame Adversary
Plenty of green permanents to reduce the card's cost and the situation you can put the table in with deathtouch or drawing cards is interesting to consider.

The Royal Scions
The starting loyalty is a little high, but each of the effects, including the ultimate, are basic enough that the planeswalker is worth considering.

Stormfist Crusader
A unique way to accelerate the early game by rewarding more cards with some life loss.

Stonecoil Serpent
Great at any point on the curve and protection from multicolor is extremely relevant. Additionally, having another way to put an artifact into the graveyard for any delirium strategies.