神仙 shen xian
This translates to deity. In a way, it refers to those with an immortal body, abilities that are supernatural and able to transcend the earthly world to supposed heavens.
In Chinese culture, we see that this is extremely popular amongst drama plotlines. In fact, recently the drama 三生三世十里桃花 (san sheng san shi shi li tao hua) has garnered so much popularity in China that it is now the top rated drama. As of 1 August 2018, the series has reached 50 billion views, becoming the most watched Chinese television series. The plot surrounds the two main characters, a female deity named Bai Qian and a male deity named Ye hua.
This is only one example of the many popular drama series that uses 神仙 as main characters.
Another popular saying surrounding 神仙 is to refer to people that you admire, or that they have such amazing abilities that they are akin to a deity.
An example to use it:
哇你好像神仙啊，真厉害！
wa ni hao xiang shen xian ah, zhen li hai!
which translates to "Wow you are like a god/deity, you are amazing!"