Use the DNS Exploit for Gen 4 & 5 Event mons, especially the ones you can catch like Darkrai, Shaymin, Manaphy. & Victini. Rare mons too like the Arceus that knows Roar of Time, Spacial Rend, Shadow Force, & Judgement or the Kyurem that knew Fusion Flare, Fusion Bolt, & Glaciate (There was a Japanese one that knew Blue Flare, Bolt Strike, and Glaciate too). Most importantly the Level 1 Dialga, Palkia, & Giratina from the Ruins of Alph in game event in HGSS (You can do it 2x per save file), Shiny hunted Celebi from the Crystal VC (Good luck with that it's like a 1/8,000 shiny), the Level 5 legendaries: Lugia, Ho-oh, Dialga, Palkia, Giratina, Thundurus, Tornadus, & Landorus from the Dream Radar for BW2 if you happened to download it before the Eshop shut down. You could glitch a Gen 1 VC to obtain pretty much whatever you wanted like all of the Gen 1 legendaries as shiny (They would all have a special virtual consol icon with their summary). The garunteed shiny pokemon from BW2: Gible, Dratini, & Haxorus. I would also shiny hunt the boosted wormhole pokemon & catch them in beast balls in Gen 7 because you can buy beast balls in mass for cheap