double sided card mtg modal faced cards Evaluating All Thirty-Six Modal Double-Faced Cards General - Dual Faced Cards

Lets get on the lifegain plan using this combo

But the portal it opens has lots of demonic arms and hellfire reaching out and tearing apart that human who's probably trying to make contact with the Phyrexians

Need proof

This means it's not possible to cheat creatures into play out of nowhere (which madness can do), but it also means you're granted more flexibility, because you can cast a spell for its mayhem cost at any point during the turn in which it was discarded (rather than having to choose immediately as per madness rules)

Season of Gathering (BLB) $12.64 Season of Gathering is shaping up to be one of the best green card draw effects in Commander