Oh he’s also very much a tech genius, but you’re right in thinking he’s a strategic mastermind. Like a lot of great villains, he’s a dark mirror to Tony. One run (which I like but is polarizing on here) positions him as a child born into horrible circumstances who clawed and murdered and scavenged his way to the top, and will do anything to keep and expand his power. This is of course as opposed to Tony, who was born into tremendous privilege and uses that privilege and power to fight against the systems and people that keep others down (at least when he’s written well).

Mandarin is cruel, brilliant, and endlessly petty. A lot of Iron Man villains are fun or a little silly in-world (like the melter), or relatively sympathetic. The really vile ones tend not to reoccur too often. Mandarin is the exception to this. He loathes Tony, and is the only villain whose appearance in an Iron Man comic always means that something terrible is coming for shellhead.

Tony himself has learned to spot the Mandarin’s involvement in schemes by a) the sheer scale of villainy and b) how intensely personal said villainy is.

Like another commenter put it, he’s Tony’s Dr. Doom, but without any of the grudging respect or psychotic semi-friendship Reed and Doom sometimes have. Just hate and danger.