Sometimes you can't beat a good bastard in a story, someone who will do underhanded tactics to win, kick a defeated opponent when they are down or is always about the reward after they complete a quest/job.
Been reading The Greatest Estate Developer and it's your standard Isekai tale, guy wakes up in the body of a lords eldest son he read a fictional story about and knows they are in massive debt, all die to be the catalyst for the knight that serves them who's the MC. So he uses his architectural knowledge to change their fortunes but does it in the most bastard way.
He'll bitch slap an entire college full of stuck up nobles because he can get away with it, kurbstomp his opponent after he wins a duel to then trick him into exile, force a water contract on a rival noble that essentially binds his future generations to pay him extortionate fees and much more. This series jusy passed 100 episodes and has some of the best faces I've seen from a series.
So whether it's Leon from MobuSeka or Amos from The Expanse, who's your favourite fictional bastards?
Hm... very difficult question. There's a lot of fun ones. I prefer the "bastard with a heart of gold" archetype myself.
Off the top of my head from anime:
Onizuka from GTO - The man who'll teach the worst high school shits a lesson, even if he has to get his old gangs that he led involved, go out on dates with their moms, or tie up a bunch of girls, strip them, and... well... I'll just stop there before continuing.
Lelouch from Code Geass - What a guy to watch, I don't want to spoil anything about it.
Alucard from Hellsing Ultimate - You can tell he immensely enjoys the killing, fear, pain and slaughter he gets to inflict.
Naofumi from Shield Hero - His is more just a response to the shitty world, but its funny to see him defy everyone's expectations by being an industrious pragmatist, he never does anything for free, and will bully, threaten, and use slave-binding magic to ensure loyalty
ironically and cleverly his has a positive effect on the world.Others have already said Kazuma from Konosuba, who's an excellent one, very funny.
Lordgenome from Gurren Lagann - Just watch it.
Fuhrer Bradley or Scar from FMAB - Talking about this is kind of a spoiler, so I won't.
Yusuke or Hiei from Yu Yu Hakusho - The former is a selfish, uncontrollable and violent (but deep down good-hearted) punk, the latter is a ruthless villain that, well... you'll see. They go through some great character development, especially Yusuke.
Joseph Joestar from Part 2 - He's just great kek. He has no concept of honor in a fight and will use anything and everything to his advantage (including cowardice), along with mentally fucking with his opponents.
With Alucard the bit with the SWAT officers exemplifies his bastardness.