From Volume 59 - Chapter 579 / Season 8 Episode 488. The Whitebeard have suffered a crushing defeat, with the death of their captain and Luffy's brother, the Marines take advantage of their retreat, killing as many as they can. But Koby can't stand to see this senseless bloodshed, and stands up to an Admiral, at the risk of his life.
From Volume 56 - Chapter 550 / Season 8 Episode 459. The unfortunate execution of Portgas D. Ace has arrived. To the world, this is a ploy to anger Whitebeard and start a war with one of the Four Emperors of the Sea. To us the audience, it seems like it'll also be a blow to the Revolutionary Army. Given Ace and Luffy are brothers, they both surely share the same father, though Ace seems to have some sort of grudge with Dragon. But Sengoku and Garp know the true meaning, and that's to end the life of the most likely candidate for future Pirate King!!!!
From Volume 1 - Chapter 2 / NETFLIX One Piece - Season 1 Episode 1. After being trapped in a barrel and found by Coby, Luffy encounters Alvida, a fearsome pirate with a brutal mace. Though he is not a bounty hunter after her like she'd hope, he is still an intruder, one that she intends to kill. Luffy does not have any fear, because he's the stretchy kind of pirate!!
(Note: Yes! I am making moment comparison posts with the live-action series, I love it!! You're all free to make requests, but keep in mind that the moment has to have happened in the manga, or at least the anime. As much as I liked scenes like Nami and Kaya discussing money, or Arlong threatening Buggy, I can't post these scenes because there's nothing to compare them to. The same, of course, goes both ways. So scenes like Usopp disbanding the Usopp pirates, or Zoro stabbing himself against Cabaji, can't be done either.)
From Volume 1 - Chapter 7 / Season 1 Episode 3. Captain "Axe-Hand" Morgan is defeated, and it's time Luffy and the others make their departure from the island. But if the Marines find out that Koby was working with them, or worse, that he used to work for "Iron Mace" Alvida, he'll never get to join the navy.
