
Originally Posted by
M3J
Whitebeard protected Fishman Island at no cost and loved his crew like his son. The boss enemy in the arc where we first met Sanji did not care about his crew at all. Even Doflamingo punished Bellamy. Roger was the same - he destroyed lives, but he also protected his crew and was a good guy. Hell, for all we know only the pirates (especially the bad ones) were probably the only ones affected. Crocodile was evil because he was willing to kill innocent citizens and find the powerful weapon to control in Alabasta. Luffy needed Crocodile, hence why they worked together. Crocodile also saved Luffy because he hated the Marines more. Bon Clay was never evil, he was an enemy but not evil. He never killed or hurt anyone, and from his first interaction, he showed no signs of being evil. He even got along great with SHP and is one of the main reasons why Luffy was able to break out of Impel Down, or even survive it in the first place. Bon Clay proved he wasn't evil.
Robin didn't kill SHP or even fight them, despite many chances to take them out. Even back when she was an unknown, she never attacked Zoro or Luffy, and she even saved Luffy twice. And while Luffy did fight Marines, he never killed any single one of them, to my recollections. I don't think he's killed anyone in the manga so far.
While most of these characters have been on the side of evil, they haven't done unpardonable evil acts, or they made it up in some way later. Blackbeard not only killed his nakama, but he captured Ace and had him imprisoned, which led to his death at hands of Akainu. He also told Luffy that Luffy was the target, but Ace chose to keep goin after Blackbeard instead. Not only that, but Blackbeard also had a hand in Whitebeard's death, at the least, and he's currently seeking Devil Fruit users and stealing their powers or killing them. The only way I can see Luffy and Blackbeard working together is if Ace is still alive, and Blackbeard was planning something for the good of others. Blackbeard wanted Ace as his nakama because of his power. He didn't care about Ace at all, and while he didn't want to kill Ace, Blackbeard is still the reason Ace is dead, even if he never killed Ace.
Yes, but look at their actions as well. Do you think Arlong as he was would be friends with Luffy? No because Arlong still tortured Nami and would still hate humans. Only way they'd get along is if they had a common goal.