mhh, am i the only one who cant get the fairy godmother card to work as a material (for getting the boost ofc) there is no top-middle red button like metioned :c
If it's not too much trouble, could you please provide us with a screenshot?
If there's no top-middle button (アルティメット化する), then that means the card you are using is not a High Purified SR+ card. However, FGM cards are supposed to be able to be used regardless of the cards you want to use it on. Just drag the FGM card you want to use to the right box and then hit the 合成する button to boost it.