Colwyn sticks his hand into molten lava to retrieve the ancient throwing weapon, the Glaive. What I like about this is that clearly Colwyn, and Lyssa, are some kind of wizard who is both immune to heat and fire and can also control it to some degree. The movie doesn't beat you over the head with lore or explanations, it just presents these facts through unaddressed character actions. You couldn't have these scenes today without some clunky line about it to keep audiences from getting confused. They trusted audiences back then.