Its that itch that can only be scratched by sifting through stacks, boxes, and binders of cards, pulling together a pile thats loosely tied together by an idea, or several ideas, that are going to be simply awesome with the right commander at helm
Worst-case, this can feel like a 6-mana Phyrexian Arena
The value of X is determined only as Fraying Sanity's triggered ability resolves
Like the once-iconic Balduvian Horde, it would have to be given a lower commonality like uncommon
You proliferate
While we don't exactly know what the new firebending, waterbending, earthbending or airbending mechanics do exactly, it's safe to say that these will be tailored around four of MTG's five iconic colours