Widget for many characters issue

Hi! I created “MyCharacter” Blueprint. And I put Health and other informations in that character blueprint. Then I bind them to widget. So first, I created other Characters, but the the node I put in Widget blueprint only communicate with “MyCharacter”. How to set nodes so no matter with character the controller using, the widget still bind the infos?

And second, when Mycharacter is dead. it will destroy. Once character destory, Game will report error.

then I add “Is Valid” node, but not working. How to solve?