I think I may have said this before here, but I was always in two minds about the Might thing. In one way it seems really odd of course, but in another way it's really apt.
The most accurate word for what's meant by it as an attribute would be the French "puissance," which could apply to a physical attribute like great strength OR to force of will OR to force of personality OR to "kung fu" (skill built through repetition). It's an attribute (it's an attribute of the person) but it's neither a specifically mental or physical attribute.
Another concept that's sort of in the same ballpark was the idea of the "super stat" that Champions Online had - you pick one of your stats, a mental or physical one, intelligence, strength, whatever, depending on your "class," and THAT gets an extra multiplier when it comes to damage, and becomes the primary source of your damage.
IOW "Might" as meant in PoE is almost a "floating" attribute that's outside the realm of straight modelling or simulation of mental/physical attributes, yet it's still an attribute of the person.
It is actually the perfect solution, but finding a name for it that satisfies everyone is bound to be really difficult. "Puissance" is the perfect term, but of course not everybody is French
"Spirit" would also be appropriate (especially in the Chinese connotation of "shen"), but it sounds a bit too airy-fairy.