A White Scars successor chapter that happens to have fluff you like?
Well the BT were the most rabid fanatics of the Imperial Fists legion, lead by Sigismund "chosen as the Emperors Champion for his fervent faith in the emperor and his undying devotin to mankind" (BT codex)
so yeah, adherents to the cult as far as possible. Remember that the Cult as we know it today did not exist until several thousand years after empy bit the dust.