Arm Cannon ignore def in KRO server?

[Tuticore]

Hello friends, I would like to know if the Arm Cannon ignores def, some players told me that after some skill rebalance done in KRO, the skill started to ignore def, but I didn't find the formula. 

[Sigma]

Arm Cannon calculates HardDef as SoftDef since the beginning and there is no changing on it at the moment. 

[Tuticore]

Ty Sigma!