If one is not aware of the full potential of the junction system, and like how to get GFs to learn new stuff they aren't set to learn and where to get those items, then it is quite possible to lose to Adel. To understand the junction system is one thing, but to see its full potential is another thing all together. Without a guide, it
can take a while to fully understand the scope of how powerful you can be with the junction system.
Adel is rather fast. I remember my first time playing through the game, I went into battle, she hit me with a Meteor, before I could heal everyone she hit me with another Meteor, KOing someone. Right after I revived that character she hit him with Flare and KOed him again. I spent the entire fight healing until Adel used Ultima and KOed everyone. I tried this four more times, and despite my different strategies the fight went about the same everytime. I was stuck. At that point in the game, I didn't have nearly all the spells I could have had (because a powered up Ruby Dragon is scary and gets a Degenerator in the face before I have time to draw
),
nor did I have but one GF with Spd-J, and I had been normally leveling up through the whole game, I think Squall was at level 100 at this point. So Adel was probably at her highest level, and I didn't have but one character with Spd-J, nor did I have the proper spell to fully max Spd in the first place. On my second playthrough, I got the hang of item refining and low levels combined with stat up skills and all that fun stuff, and the game got much easier. But if you don't understand the minute intricacies of the junction system, then the game becomes harder.
I have had Phoenix revive me against Adel once. Pheonix revived me against Omega twice, but didn't come through a third time. And that's about it.