I see there is a disussion about her human form. Since Shiva is based on the deity from Hinduism, they couldn't really change her species.
Thereby also the lack of clothing.
But some say the name come from the verb "Shiver" which also is a good point since the original deity doesn't have anything to do with Ice.
It's a bit strange to have aeons/espers/GF that are so different from each other, but alongside Shiva we have Odin who is the highest god in Norse Mythology also with a human form, so we could call it aeon classes
Her design is great both in appearance and actions as before mentioned.