Has anyone else noticed the parallel of Hiccup casting his helmet aside? In both HTTYD and HTTYD 2, when Hiccup must brace himself to face the greatest threat to his ideals, he takes his helmet, throws it aside, and stares his challenger directly in the face. He takes off the protection on his head, exposing himself and his thoughts to someone who could retaliate against him.
In the first movie, Hiccup’s eye contact moves to Stoick - not the Monstrous Nightmare - as he takes off his helmet, tosses it to the ground, and tries to convince the Vikings around him that dragons are kind, amazing creatures that do not need to tear peoples’ lives apart. In the second movie, Hiccup approaches Drago to try to convince him that dragons are… oh wait… kind, amazing creatures that do not need to tear peoples’ lives apart.
And in both these scenes, Hiccup fails to convince the person he addresses - fails to convince Stoick and the Vikings in the Kill Ring, and fails to convince Drago to desist from his war. It nearly leads to Stoick’s death in the first, actually leads to Stoick’s death in the second, and both times throws Hiccup into a significant low point in his life.
It is what makes Hiccup both admirably intrepid and vulnerable in these scenes. He casts off his helmet - exposing his head and thus his mind - taking a risk to his safety both physically and symbolically to promote his own ideals.