Madness feels like a form of protection from discarding
In this sort of deck, its going to be free or close to free to cast a lot of the time, and nets you a huge twelve damage to throw around
I'm sure this ends up biting me in the butt every once in a while, but because I'm not relying on a gigantic Hydroid Krasis I can usually get away with it, along with playing more copies of Paradise Druid than the normal build because of that yummy hexproof
Here, and in Commander Legends: Battle for Baldurs Gate, the mechanic saw plenty of play in the somewhat bizarre Commander Draft events
Plague Engineer is a retro foil reprint that can greatly harm tribal decks, and this thing is worth $30
To help you know what you're up against, I've also listed each product that's going to be available for MTG TMNT as well