Lambo knew he was weak. He was a kid for crying out loud, what did other people expect. He knows that he's not as useful because he lacks the experience and the strength to protect himself sometimes, but he proved himself, time and time again.
Tsuna-nii told him to not to worry about them because he and his older brothers will protect him. And he hates that, that means he's still not useful to them. What will it take to earn their trust? What will it take to stand by them on equal terms?
"Lambo, I need you to listen to me," Lambo was shaking because Baka-dere shielded him from an attack and now he wasn't moving anymore. Baka-dere was starting to looked strangely gray and Tsuna-nii was crying. "You have to be strong for me and your older brothers okay?" Lambo just nodded, he was only eight and still wasn't sure what was going on. "Your brothers and I are going to a place where you can't follow us."
Lambo started crying, "I want to go with you guys, you stupid-heads are always leaving me alone."
Tsuna wiped Lambo tears away and dragged him down the emergency passageway he was familiar with. Tsuna turned and kneeled to eye level with him. He was no longer crying, instead took on his serious expression. "Lambo, I need you to stop crying and listen to me. I need you to run, don't argue with me. I'm not strong enough to protect you anymore." Lambo flinched, his brother was the strongest person he know. How could he not be strong enough anymore? "I need you to go down this passageway, but take the west side. Dino won't be able to pick you up anymore, so you'll be on your own this time okay?"
Lambo nodded, but he was still confused. "Why can't I can't come with you guys?"
Tsuna smiled without humor, "Because you're too young, you have to be older than me before you follow us."
"Older than you?"
"Yep older than me, you remember how old your grandpa and uncles was before they left?"
Lambo nodded. "Good, so you have to be as old as them, and the only way you can do that, is to run as far away as possible."
"Why won't you let me fight with you, why won't you let follow you guys." Lambo was pulled into a tight hug.
"You're the only one left of us and for that, you have to live, live for me, live for the rest of us, grow old and be happy." Lambo was shoved forward as Tsuna ran back to the battle. Lambo looked at the his empty fingers. He been released from his duties as the lightning guardian now and forever, so he ran, he ran as far as his legs could carry him and didn't stop, not for a long time.