A sketch of a cube intended to replicate the feeling of 2015 no ban-list Modern format gameplay and atmosphere, perhaps with a multicolour slant (deck will mostly have 3 colours with a possible 4th colour splash), and thus, having many more fixing lands than your typical list. Cards must belong to the pre-ORI era; maybe, to pre-KTK, except fetch-lands. This must be a fast environment, the 4th turn is crucial, some decks run 5-drops like Batterskull, Thragtusk, Thundermaw Hellkite and (possibly) Baneslayer.

Possible archetypes: UWx Control/Midrange/Tempo, Grixis Control, UB Control (?), BGx Midrange, Birthing Pod (also Kiki/Angel Pod?), Naya/RGWb fast Midrange (accelerate into 3-drops), BW tokens/generic "Dead Guy Ale", multicolour Zoo, URx Delver, UR Control, RB(w) Midrange (based on Young Pyromancer)...
Aggro exists only in forms of Tempo and fast midrange?

Some ideas:

• players will draft 60-card decks?
• cube multiple copies of the "staplest" of the staples (Serum Visions, Deathrite Shaman, Goyf, Bolt, Path to Exile, 1-CMC discard spells etc.)?
• otherwise, cube them in multiples?
• "art singleton" wherever possible?
• 50-60+ fixing lands + man-/utility-lands?
• run Kiki/Twin combo? Partially intersects with the Birthing Pod archetype;
• run a couple Thought Scours to fuel delve?
• draft with less than 8 people?