Hero System? But I'm in the Demon King's Army

At the Demon King's Army military tribunal.

The prosecutor barked, "Lin Qi, why is it that every battle you take part in ends with every other Demon King's Army unit wiped out, while the troops under your command make it through intact?"

Lin Qi: "How is it my fault that they're lousy? Besides, just tell me, did we win or not?"

Prosecutor: "At this rate, you'll get the entire Demon King's Army wiped out."

Lin Qi: "It's fine. I'll rebuild the Demon King's Army!"

"?"

"Can't be helped. I'm in the Demon King's Army, but I awakened the Hero System. If I don't screw over my teammates, how am I supposed to climb from ghoul to King of the Undead?"