Starting with rogue ninjas, building the insect kingdom.

No female lead + starts by defecting from Konoha
Konoha during the middle of World War II.
I was a nobody in Konoha for 18 years, and only because I was soft-hearted and saved my comrade, did I accidentally kill a Jonin.
Their true strength has been revealed.
As expected, Danzo arrived, having caught wind of it. The clan elders personally spoke with me, and the Third Hokage tacitly approved of it.
So I defected.
Before leaving, I saw off my teammates of five years and then killed two Root ninjas. Due to the heinous nature of my actions, I was given a bounty as an A-rank rogue ninja.
Later, I secretly changed my appearance and identity, infiltrated Takigakure Village, and turned it into my own lair.
I am not a bloodthirsty person. I have never liked the life of fighting and killing, and I find it difficult to adapt to the living environment of the ninja world. I prefer a quiet and comfortable life.
Controlling the higher-ups of Takigakure and eliminating those ninjas who opposed me were all out of necessity, because they were always trying to disrupt my peaceful life.
Later, the stronghold of Takigakure Village was exposed, but I did not leave, after all, I had already gotten used to living here.
To prevent any unforeseen circumstances, I also took control of Kusagakure. After that, Yukigami, Yukagami, and Hoshigami all became my bases. It's always wise to have multiple burrows, like a cunning rabbit with three burrows.
Unbeknownst to me, my lair had spread throughout the entire ninja world. In the end, the entire ninja world was on my wanted list, and I became the biggest villain that everyone wanted to kill.
Oh, and I also have a "golden finger" petri dish that can speed up the cultivation of some insects. But my success has little to do with it; it's all thanks to my own efforts.