"I taught you before. In order to control people, you have to exploit the darkness in their hearts. If there is no darkness, then you just have to create it. You never thought I would also use the same trick on you."
― Madara Uchiha to Obito Uchiha (Naruto)
" I always like to have reminders around that there is no good he can do... that I cannot corrupt."
The ability can be used to corrupt a person into doing anything. It doesn't control the victim, but it prevents them from realizing that they otherwise wouldn't do what the user suggests, and therefore they become much more malleable. A small amount of proximity and contact is needed to corrupt someone, and this proximity or contact is needed every now and again to prolong the effect.
It is easier to corrupt someone to do something minor, e.g. more corruption would be needed to get a victim to murder someone than to get them to steal. It is not impossible for the corruption to be broken, but it is severely difficult and would usually need outside influence. An example of an ability which could be used to break the effects of corruption is Belief Inducement. If the corruption is not renewed occasionally, it will eventually wear away on its own accord.
Corrupt even the most good-hearted of people.
Make a person do evil things that they wouldn't otherwise do on their own.
Emperor Shev Palpatine/Darth Sidious (Star Wars) corrupted Anakin Skywalker and several other Jedi.
The Mark of Cain (Supernatural) slowly corrupts the bearer until they become bloodthirsty killers. Upon their death, it corrupts their soul into a demon. It is even powerful enough to corrupt Archangels, such as Lucifer.
Rabids (Supernatural) are humans that have been corrupted by the Darkness, turning them more aggressive and violent, as well as being able to corrupt other humans into Rabids via blood contact.
The One Ring (Lord of the Rings) is an incredibly powerful magical artifact that grants invisibility to those who wear it, but has a corrupting effect on anyone who even looks at it.