Iron Man, Vol. 3 #31 (2000)

The Sons of Yinsen, Part One: This Ol' Heart O'Mine
Tony is investigating the fallout from his battle with his sentient armour. When the city is attacked, he sets his studies aside, and heads out to help in his old armour. The sons of Yinsen are out in force, taking out facilities housing sweatshops and other harmful businesses, without ever actually taking a life. Still, their knowledge and goals come as something of a shock to Tony when he meets their leader face to face.
Release Date: 2000