Using every time basics chemistry and physics phenomenon, he is slowly revolutionizing everything around him.
Romance goes slowly, it is purely one-sided and is purely background but it gives a "real" feeling. Politics are too, really interesting, and I'm waiting to see how things will go between the 5 heirs, Thimoty taking the first blood actually (around chapter 40 and more).
I'm maybe hoping too much, but it would be so good if the MC had the b***** to rebel against church, like in some famous English best seller...
have a double life, he has to hide to his previous disciple the fact that he's still alive to allow her to face forward, what she doesn't manage to, still loving her master (which is kinda creepy, when we read his description in his first life's end).
his morphing in Willian's awakening
His two old buddies are strong too, but, well, he sees them once in a decade, so they can't be called even supporting cast.