HMMMM I have so many floating in my head...some of them conflict I think. But my main concept of him is split between Prime dottore and one of his more mature segments. I imagine them both lean and fit, w cuts & acid burns all over, some body mods, pearling and piercing mainly...Prime is more plotting and calculating, prefers the use of coercion & manipulation. I think this segment is calmer than the rest, but still more easily overcome by emotion, obsession, fascination etc. More prone to violence & agitation, likes drugging & modding his victims. I think prime is more detached from his experiments and acts mostly out of curiosity or boredom. One scenario i think of a lot is Prime recapturing collei and brainwashing/mindbreaking her into being his daughter 🥴 I see prime less interested in penetration or relieving himself so much as just toying with collei, touching her to see her reactions & making her do things to herself or others (like Scara or Childe, or mob or whatever companions he's captured or something) voyeuristic i guess? His younger segment is more lustful, obsessed w impregnating Collei, loses his chill a lot to his thoughts, is collected but vengeful when disobeyed, doesn't do aftercare nearly as much as Prime. But yeah God i love Dottore evil doctors are like my fave thing ever 🥹 Dottolei and Dottoscara are my fave ships but I also like Dottokae and Dottoluc, I'm exploring Dottobedo in my head 🤔 plus any combination of Dotto/Tigh/Cyno/Collei works for me too... I just really like Dottore...