Fixing the battery would work for dry/dead internal battery Sapphire and Ruby but I'm not sure anything fixes Emerald. Umm, only Groudon is availiable in HG, Kyogre in SS, and to get Rayquaza you need to have seen both and show them to professor Oak.
Oh, umm normal soft resetting doesn't work in Emerald and in dry/dead battery Sapphire and Ruby because something is up with the RNG. It's 'broken' basically so you're always going to get the same frames of pokemon. Like in regular soft resetting if I turn my game on the pokemon is always going to be different, I'm not going to encounter the same specific pokemon when I turn it on over and over again. But for broken RNGS, it'll always be the same. So this makes soft resetting hard because you'll always encounter the same frames and never get a shiny unless you have an early frame. yeah, you'd need to be pretty luck for it to work. If you have any of the other games you can get most of the other legendaries through them. (Like the regis can be found in platinum, I think? and Latios/Latias can respectively be found in heartgold along with the weather trio)
Why is it considered RNG Abuse? Because unless you possess two shiny frames you're always guaranteed to get a shiny on that specific frame, ie I get an early shiny frame so at 17.4 seconds I will always get a shiny, I will never not get a shiny at 17.4 seconds if I encounter/sr for it. Understandably this makes a lot of people who hunt for shinies pretty angry because you're always guaranteed a shiny. You could do it if you want to and it's really up to you but it's never going to be a random shiny after the first shiny you encounter/starter pokemon you hunt for.
Oh, hmmm. I don't think it's possible to sr for a shiny without it being considered RNG abuse on those games? The only way I know of to SR that far in the game and have a shiny is to get a shiny starter (which would mean you would have an early shiny frame) and then sr for it later on? That's still considered RNG Abuse tho. I don't think there's a way?
Hey there! I saw that you asked if there was an album of Pokemon X Y shinies on the shiny thread. I did post a link to one there, but I don't think anybody noticed it XD. This imgur album I found on Smogon has the most images I've seen so far: http://imgur.com/a/VZ0jQ#0. The only one that's wrong is Gogoat, the picture they have of one there is a normal one.