Hi Professor.
Welcome to the forum.
I hope that you have brought some of your special skills with you.
And I was very interested to read all about you.
Moriarty is extremely intelligent, cunning, calculative and manipulative. He is also incredibly ruthless, shown by his steadfast vow to Sherlock Holmes that "if (Holmes) was clever enough to bring destruction down upon me (Moriarty), then I shall do as much for you".
Moriarty is categorized by Holmes as an extremely powerful criminal mastermind who is purely adept at committing any atrocity to perfection without losing any sleep on it. Moriarty's ruthlessness, lack of empathy, intellect and grandiosity make it fair to label him as a sociopath: he sees people as either pawns to be manipulated, or obstacles to be destroyed. As such, Moriarty will do anything to achieve his goals. It is stated in
The House of Silk that Moriarty does not directly participate in the activities he plans, but he only 'orchestrates' the events. However, he is not at all a coward: he is willing to take matters into his own hands if his hand is forced, such was the case with Sherlock Holmes.
Moriarty is not without character flaws, as he suffers from a superiority complex: he is extremely arrogant, overconfident, precocious and condescending to a fault. Other than Sherlock Holmes, he sees no other man as his equal, and even with the latter he expresses his sense of superiority over him and his willingness to torment and threaten Holmes for as long as is required. Like most archetypes in Sherlock Holmes episodes, Moriarty is impeccably sophisticated, refined and reserved. He has an excellent sense of style, speaks in an intellectual, calm manner and has an almost extravagant sense of surroundings.
I just hope that you have not brought your superiority complex with you!

layful: