It scares him. That thing he wants to hide away SCARES him and Allen doesn't get scared. But given the chance, he'd throw himself at Mirror before anyone.
Watanuki has already had his heart completely destroyed and Aeris...Aeris keeps HIDING.
And Tsuna...I don't want that on Tsuna, he's managed to be so strong and Fraz is still new and Cobra doesn't want us to see his fears.
Lacerta is so strong and brave and parts of themselves SCARE them. At least...I KNOW I can be not scary. Feramis showed me that, that if I can keep...keep something of my humanity, I can keep from becoming a monster.
I can...
I can avoid having that look you have...I can avoid it being on any of their faces, at least once...
[And she sounds so desperate as she says it. Just once, just once she wants someone to not look so stricken and afraid in front of her. She doesn't want it anymore.]