Steel Against Shadow

S1, E3: Gillian tells the story of Valroth, a powerful weapons maker who made living armor to protect his people many years ago. But the armor became too powerful and it was all destroyed except for the helmet. Jayce seeks the helmet, finds it, and after putting it on, his power is invincible. He easily defeats some monster minds. But the helmet is wicked and it takes over Jayce's body. Jayce and the power of light conquer the evil helmet, and then they destroy it.