Amongst the moon, the triad joins =
The triad joins with the moon =
"triad" joins with "moon" =
"moon triad"

which makes me think of the item "Three stars".
Using the following line, "Seek out the talent" leads me to the Expendx3-1 ability.

"I hold through life,
although it has no path" -> The talent/ability stays the same; you master it the minute you learn it.

"A wise old man,
with royalty," -> I'm not sure what to make of this. "wise old" makes me think of Experience, in the game abbreviated to "Exp" which is the first part of the ability's name.
"with royalty" could, although I doubt it, refer to the same Mordred that BG-57's riddle referred to. He was King Arthur's son. Three Stars is the treasure found on Mordred plains.

"will always lead the way,
across the third bright road." ->This is even harder to match, but it could simply refer to the finding / obtaining process of Three stars.

The last part made my guess feel unlikely, but is it Expendx3-1?