What is your source of mythic power?

[Nekroskop]

After reading through the adventure path I realized that the actual source of the mythic power for the heroes is quite underwhelming. It is the rest of the exploding ward stones.
How this leads to them having to do mythic challenges in order to rise in mythic levels never made any sense to me, so I flavored that up.
Now, in my specific campaign, the wordlwound actually exists because the players failed in the campaign before.

Failed campaign info:

My players snafud kingmaker and the stolen lands were ripped into the first world. So I made this so daamaging to the structure of reality that it opened the worldwound. The Elders of the first world were seriously unimpressed by this and cursed Nyrissa to become my version of Aarelu. I a bid to lift her own curse, Nyrissa/Aarelu shattered the bottle that contained the stolen lands and out of the shards created the wardstones. Now a part of her personality is trying to guide the players into redeeming her, while another just wants to use them to kill Baphomet and Deskari and take their place. She is also the mother of two of the PC's, while she has made two of the others into demonic halfbreeds, but that's just icing on the top.

So what my players are actually challenging is the combined lifeforce/souls of the former campaign area, represented by the voices of their former characters. So all mythic challenges I do opens them up to more souls/powers/followers that grant them their mythic powers, and I try to link their mythic challenges to something there former character would expect of them/be impressed by. To make it a bit more obscure, I shuffled the characters around, so the characters of other players are guiding new players.
My master plan is for them to gain sooner or later the commune with power ability, and then the players can coach each other from their old PC's point of view!
I am still looking for the equialent of their enemies gaining mythic energy, even though "powered by the essence of fallen demon lords" is already a bit of a parallel.

So, needlessly long intro, how do you play the mythic energy source? What do you do when a player chooses commune with power?

[Dragonchess Player]

Technically, the "source" of the PCs' mythic power is tied to their campaign trait. The exploding ward stones just act as a triggering event to "activate" the PCs' mythic potential.

[Nekroskop]

How does that work? How does being from a family of crusaders make you mythic? Or meeting a succubus? And I don't actually find that in either the trait writeup or module 3, where the traits are resolved underwhelmingly as part of the mythic progression.
I don't want to put that off, but where did you get that impression?

[Dragonchess Player]

Family of crusaders: blessing of the ancestors/spirit world.

Meeting a mythic succubus and her saving you as her first act of redemption: Desna's blessing.

Expand on the bare description of the campaign traits. Granted, some of the links are more obvious than others (i.e., child of a deity), but the way each of the campaign traits are supposed to be tied to one of the mythic paths already makes them more central than most campaign traits.

[Nekroskop]

Ah, thanks for that input. Well, I'll stay with my idea, but it's still good to know what the original intent was.