You will need to set up the character AI scripts to recognize blocking by using the AirMod plrusingblock=1/0 condition in the state where damage is given to the player.
For example, I'll show the basic melee10.fpi would be changed.
It starts like this:
:state=0,plrdistwithin=500:state=1
:state=1,plrdistfurther=90:rotatetoplr,movefore=2,animate=2
:state=1,plrdistfurther=500:animate=1,state=0
:state=1,plrdistwithin=90,rateoffire:rotatetoplr,setframe=8,state=2
:state=2,framebeyond=8 60,plrdistwithin=100:plraddhealth=-10,sound=audiobank\misc\melee.wav,state=3
:state=2:incframe=8,rotatetoplr
:state=2,frameatend=8:state=1
:state=3:incframe=8
:state=3,frameatend=8:state=1
And then it is changed to this:
:state=0,plrdistwithin=500:state=1
:state=1,plrdistfurther=90:rotatetoplr,movefore=2,animate=2
:state=1,plrdistfurther=500:animate=1,state=0
:state=1,plrdistwithin=90,rateoffire:rotatetoplr,setframe=8,state=2
;//not blocked
:state=2,plrusingblock=0,framebeyond=8 60,plrdistwithin=100:plraddhealth=-10,sound=audiobank\misc\melee.wav,state=3
;//blocked!
:state=2,plrusingblock=1,framebeyond=8 60,plrdistwithin=100:sound=audiobank\misc\melee.wav,state=3
:state=2:incframe=8,rotatetoplr
:state=2,frameatend=8:state=1
:state=3:incframe=8
:state=3,frameatend=8:state=1
I have duplicated the state=2 line where damage is dealt and in the first added the condition that the player is NOT blocking. In the duplicate, I have added the condition that the player IS blocking AND I have deleted the plraddhealth=-10 action.
Now Airmod blocking will work when you block with your weapon! You could also change the sound effect when blocking to one of the metal clanging ones in soundbank.