On release Malenia was pretty bullshit, especially if you had any non meta build. I wouldn't be surprised if since then the other builds were buffed enough to make then playable
What she did was shit on those garbage comet azur builds which is a win in my book.
As an INT fag I didn't get the appeal of comet azur.
Sure, you find later in the game a flask that lets you cast with no FP, but I'm not comfortable standing still in a game like this.
Honestly, when I fought Melania, I tried so many strategies and spells and I had fun, instead of raging.
At some point I noticed she dodges pretty good, so spells with some tracking or wide area are good. Then I noticed that most ashes die too early.
So, in the end, my winning strategy was equipping myself with staff + shield (until then, I used dagger+staff) and only two spells (Ranni's Big Blue Balls and Adula's Moonblade). That way, using Mimic, he would only use those two spells for attack and use the shield for better survivability.
The fight was incredibly hilarious, because if she went for the Mimic, I would put my Big Blue Balls in her face and if she went for me, the Mimic would do the same. For the second stage, the Moonblade performed better and the freeze procs helped a lot also.