As per latest vote results top three are Yami Asta & Mereoleona which is very interesting.
As per Black Clover Wiki below are popularity polls,
First Poll top Six: Issue 34, 2017
1) Asta
2) Yami
3) Noelle
4) Yuno
5) Nero
6) Charmy
2nd Poll top six: Issue 29, 2018
1) Asta
2) Yami
3) Yuno
4) Luck
5) Julius
6) Fuegoleon
3rd Poll top five: Issue 32, 2019
1) Asta
2) Yami
3) Noelle
4) Yuno
5) Mereoleona
6) Charlotte
4th Poll top five: Issue 40, 2020
1) Asta
2) Yami
3) Charlotte
4) Yuno
5) Noelle
6) Secre
https://blackclover.fandom.com/wiki/Popularity_Polls