The Helmbreaker is one of the most powerful attacks in the game because of how much damage it does mixed with how quickly it can be performed. It is part of what might be the fastest and most powerful mixed combo in the game. Start with the first two swings of Hacker, perform a Hightime and then finish with a Helmbreaker to perform a very quick and powerful set of attacks.
The Helmbreaker itself is very powerful and useful for ending Aerial Combat. I would generally only use it as a finisher move or against large enemies that can't be lifted since mid-air combat is one of the safest ways to fight.
