Regarding an Egg That Contains Blood: the Sayyid Has Said That the Blood Is Impure and - Jurisprudential Answers - Miscellaneous Issues, Vol 2

Ahmed al-Hasan Response:

The blood of an animal with flowing blood is impure. The blood found in an egg is either from the animal that produced the egg or from the growth of an embryo within the egg. In either case, eating that blood is not permissible because it is impure. If the amount is small enough that it can be removed without spreading to the rest of the egg, the remainder of the egg may be eaten, although it is better for you to avoid it. As for a nonbeliever who wishes to eat the impure blood present in the egg, that is his affair, and you may give him the egg to eat. Nevertheless, it is better for you not to do this either, because eating impurity or what is forbidden may become a cause that turns a person away from recognizing the truth.