Can you show me examples of characters who are nice, but evil?

Fate/Shit please stay in /jp/ with 2hu and Boatsluts.
He only did it because it hit close to home, he couldn't have cared less for Luffy's dreams or anything.

knew exactly what was coming, still laughed

That's not Red Skull. I don't think Red Skull is a nice guy to begin with.

Korgan Bloodaxe from Baldur's Gate II.
He's a Chaotic Evil dwarven Fighter with the Berserker subclass, ignores the law when he feels he can get away with it, kills whoever annoys him too much, almost certainly killed most of his last adventuring party in their sleep, but he's actually a pretty funny and garrulous guy once you get past all that and while he doesn't have much in the way of manners or tact he doesn't really act all that mean even if he's going to kill you.
One character he does nothing but insult and belittle right up until she stands up for herself and insults him right back at which point she has his respect and they stop fighting, and another is a halfling Paladin (more or less, it's complex) and he is sexually obsessed with her not because she's good looking but because she's a total badass in cobalt despite her size and and he thinks they should be friends because of it.

Still, that whole "killed his last party in his sleep for very little reason" is pretty evil.

BioWare used to have a couple characters like that for awhile actually.
Viconia was haughty and bitchy at times, but she tries chatting it up with pretty much all of the party and despite being Neutral Evil kind of was at worst selfish and so always wanted to take options that resulted in direct monetary reward and benefited her and the group.
Other then that she's hardly that evil at all.

>He only did it because it hit close to home
Nice headcanon, nothing about that was ever implied. Might as well have been because he respected Luffy for his resolve, for example or him simply feeling like it.

I mean....Xellos is POLITE (mostly), but I don't know about him being actually nice per say.
He regular puts the Slayers in situations that could fairly easily get them killed as a way of furthering his own plans, but also just because he thinks it's funny.
They survive them because they're extremely competent individuals (when properly motivated anyway), but he never seems particularly torn up when they're about to all horribly die and doesn't do much in the way of coming to their rescue or anything like that.

He's more like a manipulative bad guy character who realized that the best way of dealing with the heroes is not to treat them as enemies but to cozy up to them in person so they mostly spend time accomplishing his own objectives.

God is lawful neutral. Follow the rules, get left to your own devices with maybe a little occasional help until you die and get eternity in Paradise. Break the rules, you might get smote, you might not, but you face death with no afterlife, just pure oblivion.
In D&D terms, lawful neutral. In canon, lawful good only because might makes right.

>Nice headcanon, nothing about that was ever implied
Remember the part where he set out to hunt Luffy down the moment he realized who he was, not giving a single shit about the fact that Luffy also was a dreamer and hadn't done anything to offend Teach or anyone he cared for? Luffy's the one who cares about the dreams of others, Teach is reverse-Luffy who only cares for his own dream. That's the entire point of his character.

Of course, doesn't mean he can't be nice as long as not doing so would benefit his cause. If he would actually care about others to the point where he cuts back on his own desires he wouldn't even be evil anymore.