This is definitely a pretty close fight. It may not look like one since Alduin appears to be vastly stronger than the little guy, but Toothless has a lot of good projectiles on his side. His slight speed isn’t that bad and a good dive bomb is sure to deal some lasting damage to Alduin. That being said, Alduin’s stamina and attack power are hard to deny and his roars have the same effect as a DBZ aura burst. I don’t see Toothless being able to hold out long enough to win. Alduin wins.