What we know for sure, is that Mhoram studied the first Ward of Kevin's lore at the Loresraat, mastering it to some degree because he became a Lord. But that, as far as I can remember, is all as far as traditional scholastic education.
When Mhoram was in the Loresraat, they only had the first Ward available to them, having not found the second. One might suppose that this was because they just hadn't stumbled upon it, but I for one am inclined to believe that the reason the Lords had failed to discover the second Ward, is that they had not fully understood the first.
So when Covenant short-cuts the intended discovery of the second Ward, he gives them knowledge which they weren't ready for, quite possibly ensuring that the Lords never fully master the first Ward. We all know what the Haruchai say about unearned knowledge...Prothall wrote:"We hold the First Ward in our hands - we read the script, and in much we understand the words - and yet we do not penetrate the secrets."
I also don't recall at any point Mhoram going back to the Loresraat to study the second Ward? We can assume that he learned of the discoveries within from the new Lords, or from missives and communications - maybe occasional trips. But nothing like full-time study of the Wards which those students at the Loresraat would have had. I in fact find it unlikely that he studied there again for any truely meaningful length of time.
So at the point of TIW, Mhoram has an incomplete understanding of the first Ward and questionable knowledge of the contents of the second - he certainly hasn't mastered it by any stretch of the imagination, likely most of his understanding of it comes from students and the newer Lords teaching him at Revelstone. Not to mention that he still lacks at least one of the seven words.
This is where the potential myth of Mhoram's power arises - he awakens the Krill. But why does awakening the Krill compare to the amassed knowledge and power granted by careful study and mastery of six of Kevin's Wards? It is entirely possible, that with his limited knowledge of the first and second Wards, a small amount of equivalent knowledge gained on his own and his "secret", he had just enough lore to by-pass the third through sixth Wards for the purpose of activating the Krill.
Keeping in mind that by this point, Thomas Covenant had come to the Land and people were beginning to think differently about things. The paradox of White Gold was clear in Mhoram's mind, having seen it's power and restraint - where as Kevin had not. Clearly something wasn't quite right with Mhoram's use of the Krill, as evidenced by his hand being burned by it - so he was definitely missing something, even if he understood the basics of using it.
So, technically Mhoram unlocked Kevin's "final test" as it were, but was he really ready for it? Can we honestly say that besides his raw ability (which I freely admit was not inconsiderable), with his very limited knowledge of Kevin's Wards that he was even as powerful as Kevin's weakest council member?
Yes, Mhoram lead his council into feats of great power and restoration, but that is in part due to the Staff of Law no longer keeping the Earthpower in check - easier to use, but flawed, self-destructive. Would Mhoram have been able to make any progress at all had the Staff of Law not been destroyed?
Well.. we saw that they did, because they discovered the third Ward... of six.
Thomas Covenant wrote:"The First and Second Wards." He gestured toward the shining caskets. "The Third Ward? Did they find the Third Ward?"
I don't believe that if Mhoram could truely be compared to Kevin, or Kevin's council, those other three Wards wouldn't have been discovered - even if they weren't studied.
I don't know... this was just bugging me, and I had to get it down on paper, as it were. Thoughts?