I decided to clarify when a few of the major events of PMD/RotH were in mah comic, just to give you an idea of the amount of time between...stuff. :3
...'Cause it's a bit confusing, even to me... >__>;

The amount of time between the Ninetales curse being layed and Akuji being reborn as a Pokemon is a difficult one to decide upon.
Oh, well. I'll just put something down there. XD;

***

Akuji ruins Thorne's life. (No elaboration. Sorry. )

About a month later, Gardevoir saves Akuji from Ninetales's curse, and Akuji runs away.

Ten years later, Akuji dies and is reborn as a Pokemon with his memories still intact.

Three years later, Sanura is born as a human.

Eleven years later, Sanura wakes up in the Mystery Dungeon world as a Skitty, memories erased. (I'd say in late-August.)

A month later, the meteor is destroyed, the world saved. Akuji disappears. (Making it late-September.)

Another month later, Akuji reappears, and he and Sanura free Gardevoir from the curse. (Making it late-November.)

About two weeks later, Thorne finds Gengar and recognizes him as Akuji, thus declaring to get his revenge on him for ruining his life. (Making it about mid-December.)

***

So, that's the gist of it up to now...

And just to let you all know, I consider Ghost-Type Pokemon to be ageless. 'Cause...you know...they're ghosts. XD
So, for all we know, Thorne could be over a hundred years old! 8D

Thorne: That's not funny... T__T;

Do you even know how old you are?

Thorne: ...No...I never kept track...

Then, you have no room to say. :3

Thorne: 9__9;

And Gengar would apparently have been a lot older if he were still a human...but since Ninetales predicted that he'd be reborn as a Pokemon rather than just *poof* become one...yeah. XP
So, he's been a Gengar for 14 years in my version of the story. (Well, maybe not always a Gengar, but you get the point.)
...And Thorne is just there.

Thorne: -__-;