Dageki o Hasai

Fuku No Hasai or Crushing Blows Is a fighting style that utilizes Busoshoku Haki in one of two Unique ways. The first of which adds a secondary strike to any melee attack while the second type uses Haki as an extension of the Users body.

Ni Seikou Kenpo
Two Hit Style uses the first way of fighting, The user Hits their foe before launching a secondary haki burst on contact causing a double impact.

Shinten Kenpo
Extension Style uses the second way of fighting, the user extends haki from their body to allow for contact over longer distances or to widen the users "Hit Box" meaning a punch can make contact over a wider area than just the users fist.