In the classic French existential tradition Nietzsche looms very large, especially the explicit precedence of existence to essence, which is just a synthesis and concise restatement of what Nietzsche spent decades trying to say. It’s interesting that Kierkegaard has a stronger association with existentialism (I’m assuming you mean the French, ie Sartre, de Beauvoir, Camus) for you because for Kierkegaard, Husserl and Heidegger the subject has a primary role in the definition and expression of his essence, but he is not wholly precedent to it, he has an inherent nature. Happy new year to you as well.