21 cards where the card types include “demon” and the color identity ≤ GRUW

Balor (Commander Legends: Battle for Baldur's Gate #162)
Bloodcrusher of Khorne (Warhammer 40,000 Commander #72)
Bloodthirster (Warhammer 40,000 Commander #73)
Bothersome Quasit (Commander Legends: Battle for Baldur's Gate #674)
Chaos Balor (Alchemy Horizons: Baldur's Gate #49)
Exalted Flamer of Tzeentch (Warhammer 40,000 Commander #119)
Falco Spara, Pactweaver (Streets of New Capenna #186)
Frenzied Raider (Kaldheim #137)
Herald of Slaanesh (Warhammer 40,000 Commander #77)
Heralds of Tzeentch (Warhammer 40,000 Commander #23)
Immersturm Raider (Kaldheim #141)
Jetmir, Nexus of Revels (Streets of New Capenna #193)
Kardum, Patron of Flames (Alchemy Horizons: Baldur's Gate #58)
Keeper of Secrets (Warhammer 40,000 Commander #78)
Lord of Change (Warhammer 40,000 Commander #24)
Magnus the Red (Warhammer 40,000 Commander #131)
Nalfeshnee (Commander Legends: Battle for Baldur's Gate #678)
Oni of Wild Places (Commander Anthology #85)
Pink Horror (Warhammer 40,000 Commander #136)
Seeker of Slaanesh (Warhammer 40,000 Commander #85)
Shimatsu the Bloodcloaked (Champions of Kamigawa #186)

In the blink of an eye, they strode from deep snow to the end of this search.