I love the misfits. They know Iruma. They know he'd do absolutely anything to help if they needed it, because he already has. It's never been about him being "Iruma the demon" or "Iruma the human", he's just "Iruma our friend".
I've always hated Alzheimer's. The person dies long before their body does. It's one thing to lose someone to death, it's another thing entirely to have that person still alive in front of you asking who you are.
One of those is an act of laying yourself completely bare, body and soul, showing your affection in a way that leaves you fully vulnerable.
And the other is sex.