The idea of Dragon fall is act like a initiation combo with Gae bulg: You throw your Gae bulg, hitting the mobs and then follow up with Dragon fall, dealing a huge amount of damage in a decent area plus debuffing the mobs with the serpentine attribute - or you can just use Dragon fall right away, since it has bigger damage than Gae bulg. In this way, Dragoon would act like a captain/initiator of the team, by attacking the team’s target from afar, jumping in and debuffing them so the team can follow up and deal increased damage to the debuffed mobs.
This concept of initiator/captain is the main concept of the class, according to IMC’s dev blogs. Dragoon was meant to be a teamwork initiator/captain boss-wise class who leads his team. Thinking on that, i create the Dragon fall. The idea of literally screaming “SPARTAAA” and diving in the middle of the mobs, debuffing them so you team can follow up seems really fitting the classic Dragoon theme.