If you're saving in-browser, "they're stored in the browser's localStorage. Where this actually gets saved to on your computer depends on the browser". For easier editing, it's recommended to "do save to file. After you edit, load that file and then save it again in-browser if that's your preferred way to save".
Modifying game data carries inherent risks. A single misplaced character or invalid value can permanently corrupt your file.
"gems" : Your current currency. Increase this for infinite buying power. "level" : The character's current level. "exp" : Current experience points.
"cor" : The character's core corruption metric. Adjusting this shifts your alignment instantly.
CoC2 recalculates stats based on level and perks. If you set STR to 200 but your level suggests 15, the game will override you on the next level-up or combat. Fix: Also edit your level ( "level" ) and experience ( "xp" ) to match your desired stats. Or, use a “soft lock” by editing equipment bonuses instead of base stats.