Focusing on the surgery

Blood oozed out from the slit I made on her chest.

Needless to say, Arteria had accepted my conditions; she seemed really obsessed with this particular heart, after all.

She's acting like it's her long-lost child or something.

And that makes those input guards all the more necessary. Their purpose is simple; to restrict the heart from taking over Arteria's body or mind.

It can, however, perform all its other functions without any hindrance, like beating to supply blood and oxygen to the body; I couldn't really put an input guard on that now, could I?

It would be pretty awkward to have your heart ask for your permission before pumping blood throughout your body; that would take body autonomy to a whole new level.

Not to mention that the person would either die or always be on the verge of death.

"Oh, right," As I saw Arteria trying to look down to check what was happening with her body, I was reminded of something. "I forgot about that."