have a card that has steroids on the field than fuse other cards the card that has steroids will get attack equal to steroids # so if you have Att 4 HP 12 steroid 2 and you fuse 2 other cards it will be Att 6 HP 12 steroids 2. So the quests is to keep using steroids till you have gotten + 10 attack from steroids
fyi Lady Vamp and Journalist are good cards to do the steroid quests