How can I cast mutliple blueprint varibles to one return node

Trying cast more than one variable to 1 return node. Whats the best way to do this. I know I can make a base bp but all my bp have all been created (a lot of work). Is there a way to make all my existing blueprints children of a new blue print to add a health variable?

In the picture below I cannot attach the the other health variable to the hud bar.

i dont think its possible to make existing blueprints children of others using blueprints. maybe in c++ you could do it though. i would have made a base character class then made your individual characters children in the first place or made them the same blueprint and had variables for things like the mesh and their name.

i believe the technical reason you cant connect them both is because they inherit from different blueprints that makes them different variables even though they have the same name and type.

In bp editor file=>reparent bp. Maybe it can do the trick

open the blueprint then on the menu bar click class settings. in the details panel in the class options section you will see parent class. changing that should work to re-parent your blueprint.
just tested in 4.17 and it worked