Basic Trope: A villainous character has a code of honor in spite of his commitment to the cause of evil, and is likable as a result.
Straight: Dracūl, despite actively cultivating a villainous reputation, often refuses to commit all-out evil actions (such as killing innocent bystanders or raping women), and will explain that said actions are "unnecessary to his goal" or a "waste of resources".
Parodied: Dracūl brags about being a genocidal galactic conqueror, and all the atrocities he's committed in that capacity... while he's climbing a tree to get a kitten out of it and giving large denomination bills/coins to all the beggars on the street.
Zig Zagged: Dracūl pretends to be noble, gets on the heroes' good side, and then betrays them. However, this turns out to shield them from a more dangerous evil. Then it turns out that the shielding was completely unintentional, and to prove it, he puts a metaphorical flag on the heroes, calling that greater evil right to them. However, this is, in and of itself, a Batman Gambit: just as he expected, the greater evil interprets that flag as a trap, and avoids the heroes because of it.
Enforced: The producers don't want any character on a kids' show to be too scary or evil, so the bad guy has lines he won't cross.
Lampshaded: "You're awfully nice for someone who keeps saying how evil they are, you know".
Invoked: Dracūl, looking for an opening into a Heel-Face Turn, starts out by lightening up his evil acts, to make sure the heroes will accept him when they change sides.
Defied: Dracūl deliberately represses his more generous urges, so that he doesn't "weaken".
Discussed: "Maybe he's not as bad as he looks. Like, you know, in dramas, there's always that one bad guy that lets innocents get away because they're not involved."
Conversed: "Nah, you can always tell when they don't like being evil. See how the camera focused more on his face when he let them go? I bet he joins up with them in the finale".
Deconstructed: Being evil means having control and respect, to Dracūl, and so he is proud of his status as evil, and works to maintain it. But in spite of his image, he don't have the stomach for genuine depravity.
Reconstructed: Dracūl discovers that Evil Feels Good. Thereafter, if an evil act does not feel good, he don't see any reason to do it.
Played For Laughs: Dracūl really wants to be badass, but when it comes down to it, all he can ever actually pull off is Poke the Poodle.
Played For Drama: The Necessarily Evil Dracūl feels terrible about his misdeeds, but sees no other path, and as a result of his guilt, spares whomever he can afford to.