This script was compiled from transcripts posted in a forum and translated, which should cover the main storyline of FFXIII (although it doesn't account for parts where the subtitles say one thing but the dialogue another, such as when 下界 is read as
This site has the description text for FFXIII's items (battle items, materials for upgrading equipment, key items), weapons, shops, Optimas (Paradigms), and trophies, but not abilities. Although the site itself does include similar pages of description text for a number of other games.
These sites includes ability descriptions for each role and summon but they sometimes differ slightly in wording on each site and I'm not sure which (if either) are what is actually used in-game:
There doesn't seem to be a full script for Kingdom Hearts 2 online, at least in one place. This site has partial scripts but nowhere near complete:
(There is a similar one for the first game which has more completed but still doesn't look full: https://www7.atwiki.jp/taru/pages/9.html
This site has transcripts for dialogue but only for the Org. XIII characters:
You can find bits and pieces people are put in blog posts or the like by searching for a distinct line of dialogue, but no one seems to have sat down and constructed a full script.
For things like item names and description text, you can try searching for キングダムハーツ２ 攻略 which will bring up walkthrough sites with lists of items, but without checking them against the actual text in the game I don't know if they will be exactly what you'd see playing when playing it. The best thing to do would be to take an example of the text from the actual game (which you can probably pick out from a gameplay video) and running a search on that.
This site seems to have some for items, magic, and abilities. Even if not accurate it should give some help with the vocabulary you will see when playing the game.
This site has weapon descriptions for Sora, Donald, and Goofy:
This is a Chinese forum thread where someone seems to have been compiling descriptions for items, abilities, accessories, etc.:
Here is the script for Metal Gear Rising that I transcribed if anyone is interested, although I haven't checked over it.
Speaking of KH2, I might have a go at making a script for that next using this playlist since there doesn't seem to be one around.