What happens if you inject someone elses blood into your vein

From what I studied in Bio,

Human blood falls into three categories - (A, B, O). There can be many combinations such as AB negative, AB positive and so on.

The thing is, when a blood transfusion occurs, the doctors make sure that the blood type is exactly the same.

Let's say you're blood type is A and someone injects you with blood of type B. Then your antibodies won't recognize the type B blood antigens, and will try to fight them off. You will most likely get a high fever and if the amount of foreign blood in your system is high enough, there's a high chance you'll die.

O is the universal blood type, meaning that even if you have blood type A or B or whatever, injecting yourself with blood type O will make no difference and will do you no harm.

I'm not quite sure if I'm right but it depends on your blood type (A,B,O) let's say you have type A blood, I don't think you can receive type B blood. But that's just what I think my Bio teacher said. I was sleepy that day.

But anyway, don't do that to yourself if you're thinking of it, let a doctor do it. :o

you gain supernatural powers and the memory of their past life

You know how they say, "there is never a stupid question," there it is.

you instantly blow up

I reAly don't know but I think that it could be reAly bad for you