Bedlam Reveler was a clearly powerful card that took a while to find a good home in Modern. Any card that plays well with cheap spells is going to warrant a look in older formats, and Bedlam Reveler's rate once you fill your graveyard is very high. So why did it take so long to find the card a home?
It was a fundamental misunderstanding of how to maximize the card. The early decks with Bedlam Reveler were Izzet-based, because the first thought for anyone needing to play with cheap spells is to play a pile of cantrips. That way you can chain your spells and exploit whatever synergies are in your deck for them early and often.
But Bedlam Reveler punishes cantrips because to maximize its ability you need to empty your hand. U/R Reveler decks would often find themselves wanting to cast their namesake card but unable to do so effectively because it wouldn't net any cards. Mardu Pyromancer solved this issue by pairing Bedlam Reveler with cheap, interactive spells. Discard spells and removal with a touch of Faithless Looting to get the velocity that cantrips give you while efficiently emptying your hand only to come back once the Reveler draws you a couple unneeded lands is a perfect fit.
Today's deck follows in that image, placing Bedlam Reveler in a Skred Red shell--a deck that plays two of the most powerful one mana removal spells in Modern. The major change to accommodate Bedlam Reveler is the shift away from Blood Moon and toward Molten Rain to increase the deck's spell density, though the miser's Blood Moon remains, which is a nice touch.
I particularly like the full set of Mind Stones. Ramp spells help you empty your hand better than almost anything else, so having one that ultimately recoups the card is perfect. Jumping from two to four also opens a couple excellent lines, namely a turn 3 Chandra, Torch of Defiance or Pia and Kiran Nalaar, or turn 3 Molten Rain plus removal spell so as to not fall behind on the battlefield.
There's some degree of customization available for the flex spots here, though I'm a fan of the singleton Roast and Stormbreath Dragon as a powerful threat that dodges most removal. Hazoret the Fervent also works well here, even if it's occasionally awkward with Bedlam Reveler. The most questionable card I see is Molten Vortex, a card clearly meant to be a way to utilize extra lands drawn the late game, a function that I think is fully served by Faithless Looting.
But that's a small nitpick in an otherwise well-conceived and well-built list. There's a history in Modern of fringe decks getting a jolt when someone puts work into it and tunes a good list (Mardu Pyromancer being one example) and this list is definitely in that mold.