“Warning!! be advised that the article contains spoilers!! (Image Spoiler) İf you haven’t read chapter 305 of the My Hero Academia manga then avoid reading this article as we’ll be plunging into some genuine spoiler!”
My Hero Academia clarifies why Izuku Midoriya is resolved to save Tomura Shigaraki with the most recent chapter of the manga. During the battle against the full-controlled All For One vs the growing power of One For All inside Izuku and Shigaraki, the two powers started to respond with each other. Surprisingly regardless of the entirety of the disarray Shigaraki had unleashed during the conflict, Izuku Midoriya‘s last pledge to the miscreant toward the finish, all things considered, was that he planned to save him.
Things being what they are, Izuku and Shigaraki shaped a lot of further association than anticipated on account of their joining powers. The most up-to-date chapter of the manga proceeds with Izuku Midoriya’s discussion with the former vestiges inside One For All.
After Nana Shimura had found out if he could really kill Shigaraki for great, Izuku clarified in Chapter 305 of the series that he really saw a dream of Shigaraki’s unfortunate past and needs to save that adaptation of Shigaraki that once had his expectation squashed by injury. As Shigaraki assisted merge with the All For One power, it was before long uncovered that All For One himself had a venomous and parasitic relationship with Shigaraki’s body. This not just kept on pushing Shigaraki and fuel his contempt, however, Izuku needs to get through this external shell.

He uncovers to the vestiges that he felt a young man crying under the entirety of Shigaraki’s fierceness when their force had impacted each other. He’s fought a few villains previously, however, he regrets that they all needed to get into a fight.
Since he didn’t comprehend what made those scoundrels the manner in which they were, and still had as much assurance toward their individual objectives as they did, he contemplates whether he would have needed to battle them on the off chance that he comprehended their intentions back. It’s not as though he sees Shigaraki in that equivalent light in light of the fact that the miscreant has murdered and harmed individuals near him, yet in his heart, he accepts that the genuine expectation that All Might and One For All assisted with creating has a greater reason than to just killing.