This can be done in Practice Mode.
Fulgore's Instinct Mode charges his reactor/Shadow Meter, as well as giving access to the powerful Devastation Beam. Pause, hit
twice to get to Practice Options, set Instinct Meter to Infinite or Refill.
Activate Instinct Mode, let the reactor fill completely, and use
and all punches, default is
n_LB]. Once it hits, achievement unlocked.