I'm afraid the attack power of a certain move can't be adjusted, but you can adjust the attack power of a certain person. The method is as follows:

Open the chars folder in the Mugen directory, open the character package xxx (character name) you want, find the xxx (character name) CNS file, and you will find:

[data]

Life = 1000 character life value.

; Strength = 5000-character energy value

Attack = 100-character attack power

Defense = 100-role defense

fall.defence _ up = 50

liedown.time = 30

Air juggling = 15

sparkno = 2

guard.sparkno = 40

KO.echo = 0

Volume = 0

IntPersistIndex = 60

FloatPersistIndex = 40