I'm building a madness module which will either be 0% or 100% in a draft.
The biggest challenges are white, where I've used a reanimator theme, and surprisingly green, in which I had to dabble in threshold for the lack of "things that like being discarded".
Another thing I found is that while madness shares enablers with graveyard-matters (threshold, delirium, dredge, etc), these themes do not synergize with each other well, so I chose to go almost all the way in the direction of "discarding matters" than "cards in graveyard matters".
I'm trying to work these kinds of synergies into my cube as I reconstruct it and have looked at a lot of these cards. I haven't finished it yet so much of what I'm about to say is theorycrafting.
I agree that white's role in a theme like this is reanimator. I think the best place to house this white reanimation is either jeskai and esper control or in white midrange decks where the reanimation is more of a generic value kind of thing.
I think the best analogue to this kind of control deck are the UW Gifts Tron and Esper Gifts deck in modern where you're playing as a control deck that has graveyard synergies. In cube I see this as white reanimation being the beneficiary of blue and red spells that tend to discard cards. In my mind, this creates a control deck that does things like discards a finisher to a spell like
Lightning Axe or
Thirst For Knowledge or discarding a
Fiery Temper to
Vengeful Dreams. Some other cards that I think are nice in this type of control deck would be
Think Twice and
Deep Analysis since they allow you to get some value even after being discarded. The nice thing about this stuff is that it can also lead to a grixis deck that exploits a lot of the blue and red synergies with black reanimation. I think
Nahiri, the Harbinger is a slam dunk for the jeskai control deck as well.
The green deck I see being the biggest beneficiary is a RG Zoo type deck that benefits from being able to use removal that wants to be discarded and threats that are discounted when discarded/ want to be discarded. In this type of deck you would be using red removal like
Lightning Axe to either play more removal cheaply
Violent Eruption for your attackers to get through or as a discount for your threats like
Basking Rootwalla and
Arrogant Wurm. Some other cards that this deck could utilize are threats that can be recurred.
Vengevine,
Chandra's Phoenix, and
Hellspark Elemental all are aggressive threats that wouldn't mind traveling through the graveyard first. I especially like Wild Mongrel and Noose Constrictor with the red madness removal spells as the pump themselves.
I think that a UG Madness type deck could potentially work where the threats are mostly green and you're using blue loot spells and the mongrels to get value out of blue bounce spells like
[Just the Wind/c] and