GDDefiler, but not sure it works with the disc version.  And may not work at all.  As said it's been years since it was updated. 

If you want to edit Grim Dawn characters then GDStash is the better option.

Later expansions for TQ (Ragnaork, Atlantis, Eternal Embers) will not work with the disc copy of the game.  For that you need the Anniversary Edition on Steam or GOG.

Grim Dawn is a totally separate game, but there's no problem with having it on the same PC.  You won't be able to use TQDefiler or TQVault with it since it's not TQ.  You would need GDDefiler, although like TQDefiler, it hasn't been updated for years so may not work these days and for infinite storage there's GDStash, Grim Dawn Item Assistant, NTQV5 - Grim Dawn, Titan Quest, Diablo 2 + Ressurected, Torchlight II and Last Epoch stasher.

I was just having some fun roleplaying.

Frankly, it's refreshing to see AI voice used for art instead of swindling money out of old folks with the voices of dead celebrities.

Are you sure those words go together like that?
nargil: Oh, that's how Greek poets said it.
Oh, okay then
nargil: * wipes brow * whew!
Did you say something?
nargil: NO. I mean, *ahem * just uh, clearing my throat ha ha

You did it! Awesome!