While the majority of your app is fine, we'll need to ask for some revisions to the AU History portion. Primarily, we feel that while the Dialga/Palkia/Giratina trio is a good proxy for the conflict between Medeus and Naga, we would prefer that they not explicitly be these legendaries as our plans for these Pokemon may conflict with your backstory in the future. You'll need to alter direct mentions of these Pokemon - calling them powerful dragon type Pokemon is fine.
Accordingly, Falchion should not specifically be the fang of Dialga and the Shield of Seals should not specifically be given by Palkia. You can, however, say that they are tied to benevolent legendaries who wished to help humanity. Like in canon, Falchion will also need to be powered up before it can attain its true power; this will require some player plots. (Our precedent for Enhanced Items tied to Legendaries is that you can have them, but you'll need to put a little more work into them.)
Finally, just a few notes that we want to make totally clear: you indicated this in your app, but Marth will not be able to remember any details about the war of 500 years ago beyond the most basic things. Additionally, the way this application is written seems to be framing the War that the Saviour fought in as the humans against the Pokemon as the good guys vs. the bad guys, respectively, but we would like to emphasize that neither side was explicitly correct in this conflict, and the humans had committed plenty of terrible crimes themselves. Marth should therefore be conscious that he is less working to save humanity against the evil Pokemon gods less than he was working to save the world from the war that threatened to destroy it with both sides being at fault.
Revision Request!
While the majority of your app is fine, we'll need to ask for some revisions to the AU History portion. Primarily, we feel that while the Dialga/Palkia/Giratina trio is a good proxy for the conflict between Medeus and Naga, we would prefer that they not explicitly be these legendaries as our plans for these Pokemon may conflict with your backstory in the future. You'll need to alter direct mentions of these Pokemon - calling them powerful dragon type Pokemon is fine.
Accordingly, Falchion should not specifically be the fang of Dialga and the Shield of Seals should not specifically be given by Palkia. You can, however, say that they are tied to benevolent legendaries who wished to help humanity. Like in canon, Falchion will also need to be powered up before it can attain its true power; this will require some player plots. (Our precedent for Enhanced Items tied to Legendaries is that you can have them, but you'll need to put a little more work into them.)
Finally, just a few notes that we want to make totally clear: you indicated this in your app, but Marth will not be able to remember any details about the war of 500 years ago beyond the most basic things. Additionally, the way this application is written seems to be framing the War that the Saviour fought in as the humans against the Pokemon as the good guys vs. the bad guys, respectively, but we would like to emphasize that neither side was explicitly correct in this conflict, and the humans had committed plenty of terrible crimes themselves. Marth should therefore be conscious that he is less working to save humanity against the evil Pokemon gods less than he was working to save the world from the war that threatened to destroy it with both sides being at fault.