You can't edit a savegame. All you can do is edit an exported hero file, but then you have to start the game from the beginning (either original campaign or the Underworld one).
Read this thread: https://www.gog.com/forum/sacred_series/sacred_gold_cheats_how

Yes, you can grab it here: Sacred 2 Character Editor

No, it's about Sacred Gold, not Sacred 2. -_-

I already pointed out the thread with links to proper editors.

Yes, unfortunately, there was never one devised for Sacred. I seem to have Sacred 2 fixed in mind because I have started a new character recently.

I see a pair of editors for the original game. One for handling inventory (and changing size of items, duplicating, etc). The second is a hero editor, but not in English. Though it tries to stay within the bounds of what you could do, you could still edit your level and bump up/down the powers as much as you want.

Actually looking at it there's a couple more.

Nexus Mods - Sacred