Megillah 15: Strengths of Mordechai and Esther

On the last of the prophets, and the way the Gemara affiliates Mordechai with Malakhi. Which leads to an investigation of the big names of the day and their chronologies, specifically during this era of Shivat Zion. Again, with the conservation of biblical personalities. Also, the 4 exceptionally beautiful (apparently) women. What really links these 4? Plus, when Esther braves an audience with Ahashverosh, and she's supported by angels, and he then extends his scepter to her, in parallel to the midrash about the daughter of Pharaoh, and her reaching for the baby Moshe. Also, why doesn't Esther get the king alone? Why does she need Haman to be present? (A lot of opinions, as Chazal chime in)