I have had my iguana, Mr. Ted, for - I dunno... maybe 10 years now, and if he EVER went through a breeding season I haven't noticed the change. He does get more orange at times than what is normal, but his demeanor doesn't change.
Has Ignatius (good name by the way!) changed in color recently? You mentioned that his behavior got worse when/after he saw his previous owner, so I kinda ran with that when it could be hormonal.
Susan also wrote:
"get him away from the cage where he cant see it so hes out of his comfort zone as they can be very protective of their cages."
That's kind of why I asked if you allowed him to roam freely. Might be worth a few, sessions with your cat safely out of the area, to observe if his attitude improves.
At this point, almost anything is worth a try.
I might also suggest slowly walking him around, while he is securely wrapped in a towel and held firmly against your body to prevent too much of a struggle, and talking to him and showing him around your house.
Mr. Ted seems to love his daily morning walks like that. They are curious animals and seem to enjoy checking everything out.
I would expect the struggle to be less and less with each walk.
But again, be careful! Don't allow him near your face until you fully trust him. An iguana bite can be a serious issue. Especially with a big boy like you have!
FIVE feet? I'd love to see pictures of him!
Please keep us posted on any progress.