Alastor Moody is, of course, a difficult character to think back on because most of our experiences with him--weren’t actually him
Regardless, he was still an important character, one of the few characters who was in the Order of the Phoenix during both Wizarding Wars. A brave and skilled wizard he was also a good judge of character (Igor Karkaroff), giving (Tonks was his protégé) and he didn’t care too much about what others thought of him—only considering the opinion of those he deemed worthy.
What I think most about him, is he gives us a glimpse into some mental illness, disillusion and how Ron would be in his later years with PTSD. Even as a high-ranking Auror, people mostly avoided him as he had become a bit paranoid
Just because you’re paranoid doesn’t mean they aren’t after you
after all his years serving as an Auror and all those he had put away. He had limited friends he felt he could trust and had shown to have many scars showing all he had been thru. In the brief moments with him, he showed to be sentimental and trying to form human connections where he could and appreciating them: giving Harry the original Order of the Phoenix photo and his relationship with Tonks
PS Very glad Harry worked to get his eye back