Heya! Searching for a BL novel I read a couple of months ago. Basic premise - MC dies and reincarnates in this novel where his role is that of a wheelchair-bound small villain. MC was a genius research scientist/ engineer in the previous life & decides to continue his research in this life too. ML (don't remember how) gets the ability to read MC's mind (only MC I think) & he gets attracted to the 'gap moe' between MC's external persona (gloomy/ expressionless/ serious) vs his inner cutie (represented by this weird power in a chibi format)
I know a few novels where ML can read the mind of MC, but don't remember this one. Perhaps you can check this list. I don't know most of these novels, so perhaps you can find it there. The first one on the list mentions MC having a disability with his leg, so perhaps that's the one?