I suddenly found myself wondering: How many times have we seen someone get a blood transfusion from a super-powered being? What were the side effects? (If any.)
I'll offer two examples, one from DC and one from Marvel, to start the ball rolling.
One memorable case was in "Superman’s Girl Friend Lois Lane #17." Story title: “Lana Lang, Superwoman!” (Cover-dated May, 1960; written by Jerry Siegel.)
Superman suddenly offered to give blood transfusions to both Lois Lane and Lana Lang. Although he didn't explain his reasons right away, it turned out that the purpose of the exercise was to let both ladies suddenly acquire exact copies of all of his own superpowers, especially the invulnerability, for the next several days. (Why this was necessary is a long story, but let's just say it saved their lives when the time came.) Superman was able to calculate precisely how long the newly-acquired superpowers would last in each case. While the good times lasted, Lois and Lana were each wearing distinctive costumes and calling themselves "Super-Lois" and "Super-Lana" as they flew around doing good deeds. Then it all wore off, with no lingering effects, good or bad -- at least, not to the best of our knowledge!
The implication seemed to be that Superman could do the same thing for just about any Earthwoman or Earthman, essentially "powering them up" to his own level, if he cared to keep donating blood. (But as far as I know, in the remaining quarter-century of the Pre-Crisis era, he never again felt the need to repeat that stunt.)
And to cite a similar example from Marvel: In "Savage She-Hulk #1" (February 1980), in a story written by Stan Lee himself, attorney Jennifer Walters became She-Hulk after her cousin Bruce Banner gave her an emergency transfusion of his own (gamma-irradiated) blood. In her case, the effects lasted a heck of a lot longer than they did for Lois and Lana in the Silver Age DC story I mentioned a moment ago. (Mainly because Stan obviously wanted to create a "permanent addition" to the roster of superheroes in the MU, whereas Jerry Siegel definitely was just doing a "temporary plot device" type of story which was never intended to have any lasting consequences.)
So the question is: How many other stories can you recall that went along the general lines of "I got a blood transfusion from a super-powered being!"? Did something good happen to the recipient of the blood? Or something bad? Or no more than you'd expect from any blood transfusion? Or what?
Note: I'll be happy to hear about relevant stories from DC, Marvel, Image, Dark Horse, or any other publisher. Including TV episodes, movies, etc., which had superpowered entities donating blood to someone else. The more, the merrier!