Subject: End of an Era Busquets – Lost Icon Chemistry After Applying Badge

theonlyoneharith​ End of Era cards get a chemistry boost based on their card type (i.e. rarity). If you change the card type, you will lose the chemistry boost. That's how cosmetic evos work in FC26 and FC25.

You will not be able to revert evolution (regular/cosemtic/badge) once it is applied. One thing you can do now is, wait for chemistry boost evos like cornerstone.