So yes, mister segundus is indeed a precious baby cupcake
But if you think he is JUST a precious baby cupcake you are so wrong
The man risks missing out on seeing the first piece of English magic done for some 300 years because he refuses to play Norrell’s game and deny his identity as a magician. He pays attention to Lady Pole’s protestations of agency and does something about it; he refuses to let Childermass threaten or distress Lady Pole, despite the fact that Childermass is the servant of Norrell - and could, for all Segundus knows, bring the fury of the ‘greatest magician in England’ down on him. He can see the Gentleman’s curse! John Segundus, ladies and gentlemen, is a freaking marvel.