AnonymousSong

You can save it as a screenshot to your PS4 but it has to be done individually, I believe. Open the photo in the Photo Album, open it to Full Screen with X, and then Share with Square. It'll give you the option to save it there

The percentages work based off what the other accessories percentages are. For example: I have the Royal Ribbon (40% in all), Ribbon (30% in all), and Cosmic Chain (20% in all but Dark). So my resistances are 66% for everything but Dark which is 58%
The math is this:
The Royal Ribbon gives me 40% off of the base damage, let's say 100. So instead of getting hit for 100 points of damage, I get hit for 60.
Next, the Ribbon protects against that remaining 60. So 30% of 60 is 18, so my damage is down to 42.
Last, the Cosmic Chain takes off 20% of the 52, bringing it down by 8 points to 34
Hopefully that makes sense?

Here's the locations for all of them once you beat the game!
0 - Keyblade Graveyard Labyrinth
1 - Olympus / Corridors
2 - Olympus / Apex
3 - Twilight Town / Old Mansion
4 - Toy Box / Kid Korral
5 - Toy Box / 1st Floor
6 - Kingdom of Corona / Cliffs
7 - Kingdom of Corona / Field behind Orange Flan
8 - Monstropolis / Power Plant Tank Yard
9 - Arendelle / Icy Labyrinth Middle Tier
10 - The Caribbean / Huddled Isles Exit
11 - San Fransokyo / West Tunnel Exit
12 - San Fransokyo / North District (Nearby Circle Roof)
13 - Keyblade Graveyard / The Badlands
14 - Keyblade Graveyard / Battlefield