He originally had a Level B Plasma Armor-Piercing Bomb skill, which also had an armor-piercing effect. If he added the Armor Piercing special effect, that would be double armor-piercing; indeed, even tank armor couldn't withstand it.
However, this armor-piercing effect wasn't omnipotent.
When dealing with energy shields, the armor-piercing effect wouldn't show.
Lu Heng then asked, "Do you have a backup? If the Spirit Injection of Armor Piercing isn't successful."
Lin Zeyu quickly nodded, "Yes, this Energy Shield Penetration."
Lu Heng saw the backup materials he had prepared, raised his eyebrows slightly, and said, "You're quite good at picking."
The Armor Piercing special effect was ineffective against energy shields, while Energy Shield Penetration was designed specifically for them.