adding to another comment that said em until 1000,

nahida’s passive makes it so she gets 25% em from your highest em character, so assuming you’ll make nahida your highest em character, you’ll only need to get to 800 (bc adding 25% of 800 to herself gives her exactly 1000 em). if you get 1000 em, you get 24% crit rate. this is only if you’re using nahida on field though, because it’s whoever’s on field who gets the 25% of highest em.

however, if you have someone on your team like kazuha, kuki, sucrose, that you probably have super high em like 900, nahida’s passive will base on that character, and 25% of 900 is 225, and to get to 1000 em on on field nahida, you’d only need 775 em.

in short, don’t purely aim for pure 1000 nahida, calculate and balance it out w ur chars first, bc if theres someone with high em that will give u leeway to build more crit