Help with Dawngrasp Story Book of Mercenaries?

Alright, so I’m stuck on Dawngrasp’s story, or more correctly put, the Onyxia battle, since Onyxia counters everything that I try to do, and since my minions that aren’t the other mercenaries are god awful, I don’t know how to deal damage to her and win. Help please?
(And yes, I know that I’m a mage, but I don’t have any spells that deal damage directly to Onyxia, except for when I get one from one of those weak, stupid Wand Thieves.)

are you talking about the book of heroes…you fight that dragon on stage 3 on up… i stuck on the 6th stage …and if i think the stage your talking about where it makes spells try not to put out minions and be patient… that how i got her

Your journey has not even started, actually. The 7th challenge is not a game anymore, something is wrong.

If its the first encounter just search for ways to summon big minions and heavy damage spells like pyroblast, its more than enough to beat her.

Why haven’t these fights been nerfed yet? The difficulty is ridiculous and completely down to RNG, need to draw god-like and somehow have your opponent not draw perfectly, I am on the 4/8 battle with Raid Boss Onyxia and well past my 10th attempt.
Giving up on this, so stupid, I only play these casually for fun and this just isn’t fun, fight seems broken, ally minions should have revive otherwise the fight is impossible, opponent has a 4 mana 10/10 that comes back every 3 turns, there just isn’t burn in the deck - the enemy has ignite, the only way of getting face damage spells is through spell discovery and only certain cards are discovered so no way of going infinite spell value.

Broken. Sad, I wanted that last card pack…