But corruption doesn't mean "in turn betraying everyone" here. It's all kinds of "moral degeneration". I like about 1/3 of the games tagged here with "Corruption", so I can't use that by itself. If it were about the corruption tag, it's not only about the protagonist being the agent of this corruption in other people, but it's specifically about that corruption having bigger impact than just the individual.
This is a problem between western and japanese interpretation of corruption genre.
90% of corruption western material is a stories about sluttification in fact. At the start heroines can be frienldy with protagonist or dislike him, but they always ends as his sluts. It seems like this is the western look on the corruption theme.
The Japanese tradition of corruption genre pursues other goals. Works in this type of stories are uses the tag «akuochi» — fall to the devil side, and this is means what it says. Heroines starts as warriors of justice, pure and innocent girls, or just good people. But in the end they are choosing the devil side. The progenitors of this genre are old sentai shows in which some of sentais were brainwashed by the villains for an episode or two and fighting with their former friends on the evil side. Mahou shoujo shows also made a significant contribution. Especially evil trasnformation of Chibiusa and some other mahou shoujos. But the most spicy was a trope when the evil organization had a method to transform a human into a monster. Mirror saga in Sailormoon is a perfect example. The antagonis searched the pure mirror of soul. Every episode her servants kidnapped a person that could have a pure soul-mirror. 1) They extracted mirror,
2)mirror dimmed because it wasn't pure,
3)person with dimmed soul-mirror tranformed into a moster of the week.
Sometime these persons were women which transformed into a female-monsters and that trope became a sexual fetish for some people.
So the trope with heroine becoming evil soon migrated to visual novels. At first it was just the bad ends, but, as time passes, japanese market got the games entirely dedicated to the «akuochi» genre. Maika games, Venus Blood series, games from Lusterise — they are all famed for the stories when the evil side winning, heroines becoming evil and betraying/killing their former friends and even humanity. Sometimes you play as a villain coquering the world and it's heroines, sometimes as a hero and becoming an object of betrayal and death in the end.
Actually there is a problem with tagging on this site. You were misled with corruption tag because you searched sluttification game. And I in 90% of cases find myself deceived here in search of games about heroines falling to the evil side. Because both of this type of stories are tagged here as «corruption» games.