fantasy creature, Yagluth, boss, Valheim, glowing runes, exposed bones, fire weakness, frost resistance, summoning ritual, ancient stones, forest clearing, misty environment, twilight lighting, low angle shot, action pose, magical barrier, vulnerable back, cracked skull, summoning stance, ethereal glow, high detail, realistic textures, dynamic shadows, epic battle scene, Norse mythology, enchanted forest background, dramatic sky, intense combat, strategic positioning, teamwork, co-op players, fire arrows, frost resistance potions, protective gear, enchanted weapons.