I feel personally approached. I love
madness, and even though red is clearly the main color for the theme, while green and blue are the supporters, there is quite a bit going on in green.
My enablers:
There are more, but they start getting worse (
Stampede Driver) or pretty expensive mana wise (
Gurzigost). However, green is really well suited in terms of payoffs, although most of them don't literally have the word madness on them. They are just great cards to discard and beat your opponent with them. Here are the ones that actively get better when discarded:
However, there are also some, that don't mind getting discarded, as they still keep a lot of value:
Add to this the many cards that profit from having certain cards (or a certain number of cards) in your graveyard, like
Elvish Reclaimer or all the Delirium/Threshold stuff, and you got yourself a nice package. It is enough for even at 680 cards, that sometimes a green, non-red deck with madness synergies comes up. Here is one exmaple: