Quote Originally Posted by CaptainNoobCN View Post
3 different element kami? i can get 1 of them in main team and the other 2 in sub team, right?
According to the google translate of the JP wiki of one of the eidolon that has the 70% buff, it needs to be the 5 main units of your main team including your soul. They also mention it's a rather difficult or questionable to use these kind of eidolons as main because if mismatching sub himes in case one of your main dies, it negates the effect altogether meaning you get nothing.