As I've no access to a 3DS currently, (otherwise I'd love to figure out the process here), I'm hoping some kind soul with a bit of extra time (and a 3DS with homebrew?) might be able to help!
What I *do* have access to is a Mac with pkhex, a DSi XL and an R4 card with pkmnchest, so if I were to receive a new gen5 save file, or simply a pk5 file, I should be able to take it from there!
I've only got 2 shiny pkmn in my Crystal sav file (attached, via emulation and extraction from R4 card) and I hunted them for quite a long time, so the emotional attachment is silly but real. They are Quilava and Smoochum, aptly named "Starshine" and "Sugababe," respectively...
I believe the next step would be to inject the sav into a virtual console rom, then utilize the poketransfer app(?), Pokemon bank(?), OR a homebrew app (of which I'm blanking on the name) to transfer / convert for compatibility into a gen5 save file or pk5 file.
MOST IMPORTANTLY I'm looking for the most direct and legitimate route that wouldn't involve manually adjusting any of their stats, and instead being able to see what natures, abilities, IVs etc come out on the other end. Thus, why I'm not really interested in manipulating them in any fashion via pkhex or other apps.
Massive love to anyone willing to help!
Pokemon - Crystal Version (USA, Europe).sav Pokemon G5 - Black Version GIFTS.sav