Welcome to my Commander Cube! The goal of this cube is to promote powerful deck synergies without resorting to easy infinite combos or low-risk, "auto-include" cards that are rampant in commander.
You will notice that a lot of EDH "staples" are not included in this cube. Instead, this draft environment rewards building around synergy over individual, high-impact cards. Rhystic Study, Smothering Tithe, Dockside Extortionist, Cyclonic Rift, Tooth and Nail, and the like are all strong, but are the type of cards that are independently and generically good.
In a similar vein, overly aggressive mana acceleration like Sol Ring and Mana Crypt are excluded, and Commanders that are all-in-one engines and payoffs are excluded. Basically, I want the draft environment to be interactive and minimize the types of cards that make players feel as though every other decision or interaction made earlier in the game was a waste of time.
However, that does not mean the cube is not full of powerful cards and powerful interactions. You can still storm-off in Izzet spell slinger with Thousand-Year Storm and Underworld Breach, or draft Selesnya and try to lockdown greedy storm players by dropping Tangle Wire with a bunch of tokens in play. The draft should allow for thoughtful game plans and reward players drafting synergistic decks.
Starting Life Total of 30
In order to help encourage an interactive game and give aggro strategies a reasonable chance in a multiplayer format, each players life total starts at 30 rather than the usual 40. Commander damage is still 21.
Expanded Mono-Colored Partners
Additionally, all mono-colored, legendary creatures have the "Partner" mechanic. This allows for unique deck building that you may not otherwise see in commander and allows for exploration and discovery of new archetypes within the cube. At the same time, it helps players create a synergistic deck in a more forgiving manner, since sub-themes within a deck are possible and could be supported by your other commander. To accommodate for the inherent increase in power the partner mechanic creates, most mono-colored legendaryies in this cube are generally considered weak or very narrow as solo commanders in constructed EDH. They still all tend to have favorable "build-around" abilities that could be used in multiple archetypes.
Limited Two-Color Partners
There is also one draftable two-color partner for each (guild). However, two-colored partner commanders can only partner with a mono-colored commander. That means it is not possible to to draft a 4- or 5-color deck. The reason for this is to 1) prevent good-stuff decks, and 2) prevent color strain in a format where commander color-identity limits your playables.
The two-color partners are:
Azorius Flicker
Dimir Discard
Rakdos Aristocrat and Aristofacts
Gruul Landfall
Selesnya Tokens
Orzhov Lifegain
Izzet Storm
Golgari Dredge
Boros Aggro Artifacts
Simic Counters