In Loving Memory

Finally, some relevant plot details

Shigaraki was standing on a pile of rubble, arms thrown out in a dramatic gesture, like he was welcoming applause from an audience that wasn't there. "Don't you see?" Shigaraki said, projecting his voice around the rubble. "One by one your symbols of strength are crumbling before your eyes! First the heroes, from Stain. Now U.A has faced destruction, and soon your symbol of peace!" Shigaraki's voice cracked and scratched, but he kept going. "What will it take? When will you understand all that is wrong with your world?"

"For heaven's sake, Tomura, what the heck?" Nana was the first to break through the silence. Shigaraki dropped his arms and looked around for where the voice had come from. "You did all this to make a point?"

"What are you doing here?" Shigaraki hissed.

"I'm a hero. It's what I do. What did you expect, grandson?"

Shigaraki grumbled and wove his hand dismissively. "You're too late. My plan is already in motion."

"What plan? Destruction? Living up to what everyone believes you are?"

"Who do you think I am?"

"You are my grandson! You didn't deserve your awful fate!"

"What fate?" Shigaraki scowled. "This is the best life I could have had!" Nana's stare suddenly turned cold and stern, very much like a frustrated mother. She started pulling off her gloves and stalking across the ruins. She floated up to her grandson and threw down her gloves at his feet. Shigaraki stared at her, confused and unsure about what was going to happen.

Nana lifted her hand and slapped her grandson.

"Huh?! What the heck?" Nana wordlessly dusted off her hands and picked up her gloves again.

"I wasn't sure if that would work," she said. "It seems your connection to the spirit world is more than surface level," she added, pulling on her gloves.

"Do you know who I am?!" Shigaraki spluttered.

"Yes, I do," Nana sighed. "You are Tenko Shimura. You are my grandson. And you have the potential to be so much better than this. I'm sad I couldn't have been there for you, for your father, and that you were given a quirk that caused your family so much destruction."

"I am Tomura Shigaraki!" Shigaraki snapped. "And I'm going to destroy this world! I'm going to destroy you!"

"You can't do anything to me, Tenko," Nana said. "I have been dead for longer than you've been alive. Even if you decide to bring nations to their knees, if you break yourself apart to figure out what went wrong, if you kill yourself trying to bring me down too, there is nothing you can do to me." Nana's tone was stern and sharp, like someone lecturing a child. But somehow, there was a calm assurance to her words. She knew she was telling the truth. Shigaraki couldn't hurt her, and he was furious about that. "I have lost everything. I have lost my family, my student, my teacher, my parents, my life. There is nothing you can take from me."

Izuku had nothing to add to the conversation. But he knew that Shigaraki would look strange talking to the air, and decided to egg him on. The distraction would help the heroes catch him. "Nana," he said. "Can I talk to him, too?"

"Izuku, honey, you don't need my permission for that," she said gently.

"Right," Izuku said, floating up to Shigaraki. He floated a little higher to be eye level with Shigaraki. "I know you don't care about the people here," Izuku said. "But I have people here that I'm going to take care of. So, because you hurt them, I have something to say."

"Hey, you're that kid," Shigaraki said, suddenly recognizing him. Izuku didn't say anything, but he did punch him in the nose. "Ow! Geez, what the heck is wrong with you two?!"