Jaina is a plot driven character with plot armor as thick as Vanessa VanCleef’s thighs.
So much like He-Man in the Master’s of the Universe comics who is “As strong as he needs to be” (and that’s cannon) Jaina has the power to do whatever the story requires her to.
Now in keeping with that when the story requires her to NOT be able to do things, she is also as weak as she needs to be. Things like teleporting into the Winter Queen’s living room when it’s 5’ away from her are beyond her.
In lore she animated an entire army of water elementals to “drown Orgrimmar” which I think is the full extent of her powers at maximum. At the very least there’s no feats larger than that which I can think of. Orgrimmar’s a big place after all, hard to drown.
Notably Thrall dismissed the elementals. Thrall also being “As strong as he needs to be” as a superpower.
It’s problematic to look at character feats in WoW because it’s not written or displayed in game with any consistency.
If you compare Jaina to some of the other “paragon” characters like Khadgar or a fully powered Thrall she’s not exceptionally strong at all. If you compare her to some other’s like Genn and Varian she’s leagues above them in power. If you compare her to someone God Tier like Malfurion or Medivh she’s completely outclassed.
Medivh is apparently off doing things beyond out comprehension at the moment. IIRC he left saying we could handle the Burning Legion because he had to be somewhere else doing bigger things.
I think Medivh is basically off doing Silver Surfer level things at this point. We have no idea the full extent of what he can do, but it’s apparently a lot.
On the one hand, this is great. It’s awesome. I want to find out the next part of the story.
On the other hand, if Medivh is off doing cosmic stuff… then we’re going back to doing cosmic stuff… and I don’t like cosmic stuff personally.
Jaina isn’t as powerful as the game would make you think she is. Most of her power comes from the staff she wields. The Staff of Antonidas, which was infused with the power of the Thunderking back in MoP. The Thunderking got his power from Titan Keeper Ra, who in turn got it from Aman’Thul.
Basically, Jaina weilds a portion of Amal’Thul’s power. The Titan who is possibly the Order equivalent of Zovaal/Arbiter. That’s why she got such a power boost after MoP. And is able to wipe the floor with every other mage, bar Azshara.