Looking at my cube, there is critical mass for: Goblins (R) Humans (all) Warriors (WBR) And, with some effort, other tribes could get critical mass running only cards that are cubeable by themselves, keeping the Poison effect to a minimum: Soldiers (W) Wizards (U) Shamans (RG) Vampires (B) I'm fine with dedicating 2-3 slots per color so each of these tribes have a Lord or some other linear effect as a nod to play them (Goblin Chieftain, Champion of the Parish, Chief of the Edge) but I don't want this cube to be mainly tribal, just have an extra layer of synergy that cares about the creature type line at a low opportunity cost
Easy to assemble and customize: Simply choose the emblem you want to use on the card display and print it in the color(s) you want along with the base and fit the emblem in the circular cutout in the front of the base
In a pinch, they can be sacrificed to gain life if your life total is getting too low
And on top of that, you could also get a foil showcase stained-glass rare or mythic rare
Within one set we were given Rafiq of the Many and Uril, the Miststalker, two impactful legendary creatures that epitomize what a Voltron deck could look like in completely different ways