The Lucifer archetype has become one of wisdom, enlightenment, rebellion against authority, a balance of "light" and "dark" or "Celestial" and "Infernal"... whereas the Satan archetype has become malicious, criminal, adversarial, Infernal...
In the original Judiac perspective, Satan was viewed as a loyal servant of God, whose role as the devil fulfilled the will of God. The Christian evolution of that perspective transformed Satan into the source of all evil, and the adversary of God and humanity. In Islam, Iblis was expelled from paradise for disobeying God, and became a force seeking to lure humans away from God. In all of these epic religions, Satan fulfills a common purpose... a powerful obstacle within that is to be constantly overcome if one seeks to grow closer to God.
The Leviathan archetype has less to do with Satan and more to do with Tiamat. Abrahamic lore of YHWH soaring over the primordial waters in his storm chariot (surrounded by four Celestial Living Creatures) and triumphing over the forces of Chaos and the draconic Leviathan before the Creation of man are reminicant of ancient Mesopotamian depictions of Marduk soaring over the primordial waters in his storm chariot (pulled by four Celestial creatures) and triumphing over the forces of Chaos and the draconic Tiamat, before Marduk reorganized the cosmos and created the world. Although Tiamat did play a far greater role in the Sumero-Babylonian mythos than Leviathan does in the Abrahamic mythos... the archetype of primordial waters and primeval chaos- and the deep, dark depths of the subconscious from which our own subjective universe manifests- is reflected in both.
How do I feel about all this?
The forces Above and Below and Within are beyond comprehension. We may subjectively experience them to some extent ourselves, if it is our will. How we choose to perceive these forces has a great deal to do with how we would experience them.
