I mean as long as the tentacle thing has a backstory behind it I feel like it is less nonsense, yes xD Like idk stupid mysterious plant or scientific experiment gone wrong, something that tricks your brain into thinking '... whatever' instead of 'this doesn't feel possible at all.' But the person below remarked that they did remodel his body, so then never mind, I spoke too soon I guess
On the other hand, I think when watching hentai my brain just shuts up anyway because I don't have any expectations to begin with lol. It's just that I didn't buy this thing here while reading but really it's not that important, I had actually already forgotten about it until I read these reactions here ( ̄∇ ̄")

The killer chip turning anyone into cool blooded great assassins is nonsense. They firstly need to have an adequate body. As long as their body isn't trained well enough, they won't be able to do the movements that their brain instructs them to do... (Just my thought)