|This article is about an alternate personality of a character, also known as a form.|
Secret Weapon Luigi was formed when Mama Luigi ate a legab at the end of the Form Wars. Mama Luigi expected the legab to increase his power, but it gave him a fatal stroke instead. When King Harkinian was revived as a cyborg, Mama Luigi's few surviving allies were inspired to do the same to their leader. They performed surgery on him and replaced most of his body with robot parts.
When Secret Weapon Luigi came back to life, he was really angry, so he started to kill people he hated, such as Brooklyn Mario. Brooklyn Mario happened to be the king of Truceland, so Secret Weapon Luigi declared himself the new king. Mama Luigi supporters were common among the surviving forms on Truceland, so he had little trouble taking control of the planet. His reign was short-lived, however, as he died fighting a swarm of attacking trolls during the Poopocalypse.
Ludwig von Koopa discovered the remains of Secret Weapon Luigi in the Excavation Day of 2110, then spent five years rebuilding him. When Secret Weapon Luigi woke up, he got angrier and started attacking Ludwig, and also half of the Mushroom Republic. He was later killed again by Terminator by attaching a mine into his body, causing a large explosion that damaged Terminator's face. When Ghost Mario brought him back to life in the year 3020, he got even angrier and ended up destroying most of civilization on Earth. He was finally killed permanently during the Gay Wars.