Something something metaphors.
Something something I have an advanced degree.
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"I need you to understand, dear, that there is a risk in even speaking his name out here in Rukongai."
Hitsugaya frowned. "Nana, you know I'm not bragging when I tell you that I'm one of the strongest reapers in the Quiet Court. Do you mean there is a risk to you, or a risk to me?"
Nana regarded him coolly. "It never does good to underestimate someone who works with shadows, Toshiro," she said. "There is a risk to all of us, no matter how small it seems. It doesn't do to pretend the risk isn't there." She waved a bony hand. "I know you aren't being arrogant, dear. That isn't like you. I only tell you this so that you know: the caution you've been exercising so far . . . you need it."
Hitsugaya drew in a breath. He nodded. "Okay," he said. "Thank you."
"I wonder if it's ever crossed your mind to wonder how long I've been around this world of ours." A soft little chuckle at Hitsugaya's sudden surprised, and more than a little embarrassed, look. "I'm not as old as the previous Captain-Commander, of course. I don't think anyone is. Who knows if there ever will be? But I was around to watch him make his mark on Soul Society, all the same, if from a distance. I've seen many things come and go in this place, and Old Nishi is one of those things that doesn't really . . . get talked about much." Nana paused. "Bad luck."
"When you say he doesn't get talked about much," said Hitsugaya, "I assume you also mean that you don't talk about him much. I don't think I've ever heard you speak on him."
"Oh, I've spoken of him," Nana said. "You just never realized he was who I meant. Don't you remember what I used to say when I scolded you? How I'd say: if you don't spit your watermelon seeds in a proper bowl or bucket, someone would come popping out of the shadows and teach you a lesson? Just pluck you up by the scruff and take you out west?"
Hitsugaya frowned. "I think I do remember that. Yes."
"Whether he came first or the stories did," Nana said, "I don't think it matters. Either the stories are about him, or he merely adopted them as his own. I can't say. Who can know the mind of a man who builds his home out of the dark. But there's certainly a reason that he took the direction west as his own."
"Why is that?" Hitsugaya asked.
"You know about the Royal Guard, of course? The Divine Generals. The Guardians of the King."
Hitsugaya nodded. "I do," he said. "To be honest, though, I'm surprised you do. The lives of normal souls are so rarely impacted by them, after all." He watched his grandmother toddle over and tap the crest he used to clasp Hyorinmaru's scabbard in place on his back. "The Divine General of the West," Nana said, "made this sword. In this way, he has become eternal. He has become a part of Soul Society, a part of the Court. No matter what he does, no matter where he is, his essence can be divined in every corner of the city where you carve out your history."
Hitsugaya nodded. "True," he said.
"These swords," Nana said, "shining, gleaming in the light, represent your work. They are the tool most associated with what you are. You kill Hollows with it. You purify Pluses with it. It connects to you. In it, a part of you is made manifest. You understand this much, don't you, dear?"
Hitsugaya nodded. "Yes, Nana," he said. "My sword is a part of me."
Nana nodded in turn. "A blade gleaming in the light, like yours, like all the blades worn by all the soul reapers across the court, casts a long shadow. It is in that shadow that he waits. Tell me, dearest grandson, what is the most dangerous thing to a sword? What can corrode, break, render useless even the most beautiful and deadly of swords?"
Hitsugaya frowned. "I . . . don't know. I'm not sure what you mean, Nana."
"Rust, Toshiro," Nana said, patting Hitsugaya's shoulder. "Rust. That is what he is. What he will be, to you. You must be ready for him. You must be prepared for him. Remember this, no matter where you go, no matter where you look: once a blade is rusted, its integrity will never be the same."