2014's Guardians of the Galaxy is a film that proves even the worst person has an opportunity to be heroic. Yondu Udonta, the leader of the Ravagers, is the best example of this idea. Over the course of two films, the character begins a slow journey to make amends for his past by impacting the futures of other Guardians. His actions inadvertently make him the real hero of the franchise's sequel.
During his introduction, Yondu's personality is more akin to a traditional pirate. He does what's best for him and his crew, and he is often looking for how he can benefit from a situation. Even when Peter Quill requested his aid on Xandar, he didn't help without ensuring he would keep the Infinity Stone for himself. However, by helping Quill, the first film gently peels back a layer of the character to reveal a deeper warmth to Yondu.
With Guardians of the Galaxy Vol. 2, the topic of fatherhood went under the microscope. Yondu's family sold him to slavery, explaining why he was such a loner, cutthroat Ravager. However, saving Quill from Ego's wrath after dropping off countless others to the murderous father was the first step in a path to his redemption.
Yondu's restraint with the Guardians of the Galaxy was next seen when he decided not to deliver Rocket Raccoon and Groot to the Sovereign. Though this began a mutiny within the Ravager crew, it also started an introspective look at him and Rocket. Through Rocket, Yondu realized that Quill was in danger with his father and immediately broke out to save him. He also used this moment to remind Rocket that it's more important to keep loved ones close before he ended up like Yondu.
Following that moment, Rocket took a more hands-on approach with the team and became a leader in his own right. He even made the hard choice to save as much of his family as he can, meaning that he couldn't rescue Quill before Ego was destroyed. Thanks to Yondu's speech, Rocket was a better hero and a better "person."
There is nothing easy about fatherhood, and the climax of the film put that on display as Yondu joined Quill in the final fight against Ego. With the power of a god, Quill took the fight to his father, buying the other Guardians time to escape. With a spacesuit and aero-rig, Yondu took one last flight to save his surrogate son from certain death. Apologizing to Quill for his rough childhood and giving him the last spacesuit, Yondu made the ultimate sacrifice.
Yondu's death and showing his love for Quill gave the character the closure he deserved. Now, Quill finally has the chance to grow into the hero he needs to be, knowing the father he had cared for him. Yondu's speaking with Rocket also helped him open his heart to the people around him and grow into a nurturing character who even takes on a fatherly role to Groot. The impact Yondu has on the Guardians is felt years later and proves he is the real hero of the film.