Izzy has been the screen through which the world has seen Blackbeard/Ed his whole life. He met Ed, who was traumatized by his childhood and desperate to run and be someone else to survive. So Izzy helped Ed cultivate his persona as Blackbeard both for pirating and for Ed's ability to function.
We've seen Izzy as he struggled to adjust when Ed started to form relationships that made him realize maybe he didn't need or want that mask anymore. It scared him and angered him. He was Ed's family, his protector, and Ed was Blackbeard as long as he'd known him because he had to be.
But in Izzy's last breath he told him that he was surrounded by people who loved him, and all he had to do was be Ed. And as he saw Ed break down into tears, over the grief of losing him, he saw the man he'd been helping protect and hide for decades. He saw Ed. And he smiled, touched his face, and affirmed that open raw emotion. That ability to cry. Because he's safe and he knows it, even when he's hurting. Especially then.
There he is.
