One way to categorize fictional characters is by the character alignment system. Originating in the fantasy tabletop game Dungeons & Dragons, this system involves nine different alignments consisting of combinations of good, neutral, evil, lawful, and chaotic. Most anime characters can also be sorted into this system.
Let's take a look at one of these alignments: lawful evil. Lawful evil anime characters typically fall into two categories: those who use the law to achieve nefarious ends, and those who value law and order and are willing to do whatever it takes to maintain it. One example of the former is Danzo Shimura from Naruto, who was happy to use Konoha's government as a means of pursuing personal power. An example of the latter is Stain from My Hero Academia, who cares so much about heroes doing what they're supposed to be doing that he starts taking out those who don't.
Even if you prefer your evil characters more chaotic, you'll still probably find some lawful evil characters on this list that you appreciate. Be sure to vote up your favorites.
King Bradley is the leader of Amestris. Under his watch, countless Ishvalans lost their lives, as did anyone else who crossed him. He uses the structure of law in order to aid him in committing atrocities.
Stain is a serial killer who has dedicated his life to taking out so-called 'heroes' who he thinks are a blight on society. While this might not sound very lawful, he's actually trying to bring society back to what he sees as morally good - it's just that he's using evil means to get there.