In the third game, Nene spends spends Hanzo's entire story route badgering him to learn the flute, so he'll have something he can do when the conflict ends, a notion he constantly rebuffs. His ending has him playing the flute while surrounded by the dead and dying of the final battle, which Nene thanks him for in her dying breaths. The last shot is Hanzo entertaining some children with his music.
In the second game, Nobunaga spends his entire story trying to unite Japan by slaying everyone in his way. But then, he slays Mitsuhide Akechi and eventually take the body of the warrior out of Honnoji in his ending. His Dream scenario, Nobunaga's Dream: Nobunaga Unites Japan has him honoring Mitsuhide's memory, by issuing an order to his troops to not slay a single man, but instead have them retreat or surrender. The mission ends with him remembering of Mitsuhide.
Third game, Nobunaga's ending. Mitsuhide is defeated, but does not die. Nobunaga lectures him a bit about how it is impossible to have everything and how things are changing as they speak, and to end it all... Nobunaga forgives him, both vanishing in a sea of flames, but hopefully to become living legends.
Remember the tearjerking and Downer Ending for Oichi's story in the second game? Thankfully, KOEI has been kind for her in the third game. Even after Nagamasa sent her back to the Oda to ensure her safety like he did in the previous game, Oichi still wants and eventually managed to return to her husband, saying that she choose to be with him. Awww, they're not a Sickeningly Sweethearts for nothing, are they?