It would depend on my sharingans ability, if I had something rigged like Tobi's space/time or Shisuis rigged genjutsu there would be no need to obtain MS and inevitably end up blind
However, if it was a basic 3 tomoe sharingan with no special abilities by nature, like Sasuke, I would obtain MS by any means, you don't have to kill a close friend to obtain MS just watch them die, a choice between two evils I would do either..as for EMS I wouldn't kill my sibling, but if they died by other means I would take the eyes.
People who say they wouldn't do either are just too weak to consider it at all
