ever 是个时间副词，意思是“过去的任何时候”。意思等于：

all the time in the past; any time in the past

它跟 always 的区别是：ever 是“曾经的任何时候，过去的任何时候，以往的任何时候”，而 always 包括过去、现在和将来的“任何时候；总是；永远”。

此外，than ever 和 as ever，是习语。不要细分，知道意思、会用即可。

You use ever after comparatives and superlatives to emphasize the degree to which something is true or when you are comparing a present situation with the past or the future. 以往任何时候 (用于形容词或副词的比较级和最高级之后) 

She's got a great voice and is singing better than ever.

她有一副好嗓音，比以往任何时候都唱得好。

Japan is wealthier and more powerful than ever before.

日本现在比以往任何时候都富有和强大。

He is as energetic as ever. 

他的精力不减当年。

《汉英大词典》

Dawn came, the sea calmed but the cold was as bitter as ever. 

破晓之际，海面平静了下来，但是寒冷依旧。

《柯林斯高阶英汉双解学习词典》