D&D Baldurs Gate Descent into Avernus Lucille. Unpainted.
Unlike devils that are seen outside of the Nine Hells, the infernal forces within Avernus have developed specialized equipment to fight demons in the Blood War. Pit fiends and greater devil generals wear magical helmets which enhance their natural telepathy, allowing them to broadcast to all the devils under their command.
Giant banners also transmit diabolical energy to the legion's weapons, allowing devil warriors wielding iron weapons to cleave into the demons' resistant hide.