Here is a breakdown of what makes his voice so commanding in those intense scenes: The Gravelly Baritone: His voice is deep, rough, and heavily textured. It has the auditory equivalent of coarse sandpaper or crushed stones. This natural rasp immediately gives his characters a rugged, battle-worn, and hardened persona. The Suppressed "Burr": Even when he is putting on an American accent (like he does as Clyde Shelton in Law Abiding Citizen), his native Scottish vocal cord thickness remains. It gives a heavy, muscular weight to his consonants. He tends to "chew" on his words, making them sound deliberate and violently spat out. The "Quiet Menace" (The Simmer): Butler is a master of the low-volume threat. Before he explodes, he often drops his pitch into a breathy, guttural whisper. It sounds like a predator right before a strike. By speaking quietly but with immense pressurized tension, he forces the audience—and the character he is threatening—to lean in. The Chest-Rattling Roar (The Eruption): When the anger finally breaks, it doesn't sound clean or polished. His shouts are guttural and come deep from the chest. The sound often frays and cracks slightly at the edges, which makes the fury feel feral, unhinged, and completely authentic. Absolute Conviction: In scenes like the "biblical" monologue, he removes all doubt from his voice. There is no hesitation or wavering. He speaks with a terrifyingly calm authority that makes his threats sound like guaranteed prophecies rather than just angry words. When he delivers that specific line you mentioned, he lets the words rumble in the back of his throat, making the impending destruction feel heavy and inevitable.