27 cards where the color identity ≤ BR and the card has the keyword “Madness” and the card types include “creature”

Anje's Ravager (Crimson Vow Commander #141)
Archfiend of Spite (Commander 2019 #14)
Asylum Visitor (Commander 2019 #103)
Big Game Hunter (Time Spiral Remastered #102)
Blazing Rootwalla (Modern Horizons 2 #115)
Bloodhall Priest (Commander 2019 #188)
Bloodmad Vampire (Shadows over Innistrad #146)
Brain Gorgers (Planar Chaos #65)
Emrakul, the World Anew (Modern Horizons 3 #6)
Gorgon Recluse (Time Spiral Remastered #117)
Grave Scrabbler (Time Spiral Remastered #118)
Hell Mongrel (Modern Horizons 2 #88)
Incorrigible Youths (Shadows over Innistrad #166)
Insatiable Gorgers (Eldritch Moon #134)
Kitchen Imp (Modern Horizons 2 #89)
Markov Baron (March of the Machine: The Aftermath #14)
Muck Drubb (Time Spiral Remastered #126)
Necrogoyf (Modern Horizons 2 #93)
Nightshade Assassin (Time Spiral Remastered #128)
Reckless Wurm (Time Spiral Remastered #181)
Revolutionist (Modern Horizons 2 #139)
Shadowgrange Archfiend (Crimson Vow Commander #22)
Skophos Reaver (Modern Horizons 2 #140)
Stromkirk Occultist (Crimson Vow Commander #151)
Twins of Maurer Estate (Ultimate Masters #118)
Voldaren Pariah // Abolisher of Bloodlines (Eldritch Moon #111)
Voldaren Pariah // Abolisher of Bloodlines (Eldritch Moon #111)
Weirded Vampire (Eldritch Moon #113)

Though this query has ended, its relics still slumber in New Argive.