Vindicating the Villain

Kayan is a villain. His task is to be a whetstone for the male lead, to make him a suitable male lead. However, the male leads he met were all defects. They all lacked motivation. Even when they had him under their feet, they were indifferent. So Kayan changed his strategy. He worked hard to bond with the male lead, and after gaining their trust and affection, he suddenly turned hostile and betrayed them, stabbed him in the back, framed them, etc. Everything that villains do, he did to the male lead. Sure enough, the male lead became monstrously powerful and very qualified to be the male lead. Kayan is very satisfied, and none of the male leads can take revenge against him, and once he completes his villain's task, he can go to the next world. Until... After Kayan completed all his tasks, the system told him: [You must return to every world you completed tasks in, and survive for ten years.] Kayan was silent: [Say that again.] System: [You must return to every world you completed tasks in and survive for ten years]