In a seperate, heat proof bowl, whisk together eggs, egg yolks, and sugar. Once combined, whisk in blood orange, lemon juice and zest. Take the entire bowl and place on top of a pot filled with 1" of water. Using a bain marie, or double boiler method, heat curd mixture over medium- high heat, stirring frequently to ensure the eggs don't curdle. Continue to stir until the curd forms into a thick, almost pudding like consistency (about 10-20 minutes). The curd should fully coat the back of a spatula or spoon without running off.