As the new owner of a completely F2P NP5 100 2000/2000 10/10/10 Cleo I feel like I have to explain why she has this specific trait.
So first off, something that often gets forgotten about Fate lore is that a servant is not literally a dead person, they have been warped by stories and legends, which accentuate certain attributes and characteristics, and regress others. Probably the best example of this is Vlad. In Fate lore, the real Vlad Tepes who lived during the 15th century was not a vampire. Because of stories about his tyranny and the name of Dracula, his servant appearances all have traits of being a vampire, whether as a soft vampire who is just a religious tyrant, or as a full blown actual vampire who drinks blood from ladies’ necks.
Now, Cleo. In Fate lore Cleopatra VII Philopator was reasonably beautiful, but not overwhelmingly so. What she was really recognised for was intellect. Cleo knew at least 8 languages, is probably the best economist of any character currently in the Nasuverse, absolutely excelled as a diplomat, and was the only Pharaoh in over 300 years to actually speak Egyptian, the language of her subjects. She is actually the Pharaoh with the most potential, even more than Ozymandias. This is shown in her servant by the fact that she can incarnate Uraeus, the divine right to rule Egypt, in the form of a snake, its true form, and in fact can do it pretty much permanently. Nitocris and Alexander can’t manifest Uraeus, and whilst Ozy can, he can only do it in the form of a boat. What Cleo didn’t have is luck. By the time she became the Pharaoh, Egypt was essentially already finished. There was nothing anyone could have done to save it.
Now, part 2. Cleopatra’s love life. Cleopatra only ever fell in love twice. The first time was to Caesar, and is probably the one that you’re most familiar with, and the second time was to Mark Antony, a Roman politician and general. According to ‘true’ Fate lore, this love was about as pure and girlish as it is possible to get. Cleo’s love life would put the corniest of shoujo manga to shame.
Now, why does Cleo in her servant form have an obsession with beauty? Like with Vlad, it’s because of the stories told about her. The stories ignored her intellect, her languages, and her diplomatic and economic prowess. They ignored her pure desire for love. The stories told about Cleopatra depicted her as a harlot who manipulated Caesar and Antony. These stories accentuated her desire for beauty. In the same way that Achilles ignored Penth’s prowess in warfare and just complemented her on her beauty, the stories ignored Cleo’s skills and just criticised her beauty. I believe that the reason she is a part of this event is because her character is basically a reflection of Penth. Cleo’s servant form accepted the beauty, whereas Penth’s rejected it.
Cleopatra’s beauty is the least important thing about her, yet it is what she has been forced to become as a servant. She is barely a step away from the berserker class, already willing to harm herself with her own NP.
This is why Cleopatra speaks of beauty.