A few years ago, I was playing a fighter in a moderately high-level campaign. I cannot remember how I offended the player with the wizard character. I did something. The player decided to kill my character. In the middle of battle, the wizard would cast a spell at my fighter instead of the creatures we were fighting. This happened repeatedly. I decided to get even.
As a high-level fighter, I asked the DM if I could create a small army of followers. I organized them as a company of soldiers. In the campaign, they would not have stood a chance against the creatures we were battling. The rest of the party thought I was being a little weird having a small army.
We started a new quest. The party marched off to explore some ancient ruin. My army followed. Just before the party entered the ruin, I briefed my troops. I handed the commander several bags of gold and some gems. I instructed the troop to start building fortifications to engage the party when we returned.
The adventure took several weeks of game time. I coordinated with the DM on how my troops were doing building the fortifications. The troops created a killing zone around the entrance to the ruin. They dug sixty-foot deep pits all around the exit filling them with spikes. The built up several berms with fighting positions. The troops built four very large ballista. The steel tipped ballista bolts were six-inches in diameter. The troops carefully aimed the ballista at the exit. They built a large trebuchet with a basket filled with barrels of oil. Everything was in place.
The wizard tried to kill my fighter twice during the adventure. My fighter barely survived. As we returned I told the party I would run ahead to check for any problems. I exited the ruin and told the troops to get ready for action. I ran back to the party. I told the party the path was clear ahead. I walked with the party to the exit. I opened the door. Shouted "Fire", and jumped down into one of the sixty-foot deep pits with spikes.
The first ballista bolt hit the wizard square in the chest killing her instantly. The following bolts slaughtered the party. The DM rolled for the trebuchet hit. It was a critical fumble. Instead of hitting the entrance, the barrels of flaming oil landed short, straight down into the pit with my character. My fighter was tough. Falling sixty feet onto spikes was just a scratch. The thirty dice of damage from the barrels of flaming oil did my character in.
That was my pyrrhic victory over the wizard. A group of low-level followers slaughtered the entire party without taking a single hit point of damage. That was my total party kill as a player character.