Downloaded save.
Resigned using SW in my USB.
Deleted my Bloodborne saved data on my PS4.
Copied resigned saved data from my usb to my ps4.
Booted the game and selected 'Continue'.
Appeared my character with my weapons...
I think this game has some crazy way to double check if you're messing with saves, because that's really weird...
More testing tomorrow.
Thanks!
EDIT: Today's test:
Downloaded again BBEUStarterSave.rar
Imported and Resigned save using SW.
Instead on selecting Continue y selected Load Game.
Result was a character named Althea lvl 999 al stats 99.
Thank you so much to both Kyoshiro and xSolutionNot!