I told you
The masked man did not even feel the chills of the flames spreading through his legs. He just knew that fire was dangerous, and got caught up in the fear that fire naturally held over men, and began panicking. His rapidly fluctuating emotions did not serve to aid him in resolving his situation, and he even forgot to throw darts towards Nero, granting him the brief respite he needed.
Nero had not spotted Henry, but he threw a couple of snowflakes in that direction even as he ran. The flames held no threat against him, and though he did not intend to attack Henry that way. He just wanted them to spread so that Henry's path would be blocked.
He ran past a couple of trees, checking to find Henry, but the scout had hidden himself well. There was a small chance he had managed to run away-