have you meditated on other essences? go to your skills outside of combat and use "essence meditation" in the Magic section.
select as many essences you can find, not all will give you something but the most important is Ayleen's to get Krystal Mode. also go to ayleen's library, the bookshelf on the left of the portal. interact with it, and ask ayleen if you can take it home. keep using it and eventually you will get a skill (mental preparation) you can use outside of combat (up to 5 times), which will double your health and magic for 5 turns.
and then try different elements against the queen. idk which one is her weakness yet.