A colossal sentient oak tree made of living fire and molten bark. The tree has a friendly but powerful face carved into its trunk, with eyes glowing like molten gold. Its foliage is replaced by a massive, roaring crown of bright yellow and orange flames, emitting sparks and heat waves. Setting: an ancient Greek-style stone arena with braziers. 8k resolution, cinematic lighting, dramatic fire effects, Unreal Engine 5 render.