The obvious answer would be “AO’s version of unlocking a new mind”. However, this statement quickly falls off when you start to get into non-Magic builds.
In AA, each mind that was unlocked allowed the player to learn a new magic, regardless of how much or little time they’ve spent learning and mastering weapons and fighting styles. Unlocking them was also a difficult task, where you needed to get extremely powerful to do so.
Awakenings on the other hand, are different for every person, and some may even forget how to use their original magic. Plus, awakenings also happen naturally as one progresses in life, although one can “awaken” earlier through training.
My theory is that awakenings are a simple way to categorize where people are in in life, like how we categorize people into youth, adults, and seniors. It is also a reflection of one’s own skills that they have devoted their time into, for example, one who has spent their entire life training with a weapon and no time into training their magic will eventually forget how to use their magic, closing off their first mind while learning to harness the unique traits and auras of their weapons.
In conclusion, awakenings are points in one’s life that can either unlock multiple minds, learn how to handle different fighting styles at once, or give the ability to control the full capabilities of weapons, all depending on the focus put into these different abilities.
Arcane Odyssey takes place on the other side of the planet. The concept of “Minds” in the Seven Seas may not have an analogue in the War Seas. They could just be the same thing under a different name, or a different technique entirely.
Or, it could be that Vetex decided to make it different. Which is the most likely explanation, since Arcane Adventures is over 8 years old, and it’s not reasonable for all of the lore to remain consistent, especially when development of both games has been so chaotic.
Also, weapon users and strength users use innate magic in their techniques. They use it (mostly) unknowingly. Without magic, they wouldn’t be able to be this strong. They just forget how to manifest their elemental magic, but they still use magic in battle.
Whether it’s minds in AA or awakenings in AO- I think it’s just different way of showing how much someone has progressed in a particular combination of combative arts. Awakenings being a far broader term.
I’d like to think that Theos’ perspective on people having 3 minds that can learn 3 magics in AA comes from his personal experience as a mage and still holds true. He is the living proof that mages can only wield 3 magics simultaneously- having lived just less than 900 years to obtain Sun, Phoenix and Mastered Fire magic.
In AO however, the ‘minds’ that Theos spoke of don’t account for mastery over martial techniques that employ magic energy. (Berserkers, Warriors, Wardens and anything in between them)
Tl;dr - Minds are an apt concept for AA as we were a mage. Awakenings in AO apply to everyone.