[Ayumu sighs, absently raking a hand through her hair as she considers just how to answer that. It's not something she particularly likes to talk about, or even think about, for all that she's faced with the stark reality of it on a daily basis.]

Because he's infected. And unless we somehow find a cure for him here – and we've certainly been trying – he's going to lose to it in the end. Maybe it's not an uncommon fate for a hunter, but it's one I'd really rather avoid.

[Especially since she'd be the one who'd have to end it for him, as his friend. As one who'd know he'd prefer that to what he would become. It isn't a pleasant topic, and she clearly isn't enthusiastic about giving details.]