Cleopatra

You should use her for academic purposes

For real though she's bursty with good np gain (boosted by both her abilities despite having just one arts card) but not as good as some star gens. Use her as a dps with Ozzy against those pesky riders and demolish them with np buster brave chains boosted by her own overcharge and imperial privilege. Ozzy does take away from her ability to absorb critical stars but also improves the odds of her imperial privilege buffing her.

FYI I've never played JP and thus have never used her and obviously don't have her but it took me like 2 minutes to find out all of that.

She is a decent SSR assassin to provide decent damage, and actually there are not so many SSR assassin to used. However she is not so versatile as Jack or Shuten, therefore it is recommend to roll her if you want to build a team for her, but not as semi-support.
But because at the same period of time, Tamamo, Rin, Enkidu, Gil, Musashi, Memelin and Grampa as Grand Assassin could burn your wallet. So her appearance is not really shinning compared with others.