I'd rather wait for Pokebank to transfer an RNGed Mewtwo/Articuno. Instead, once I actually get Shinies in X (having REALLY bad luck chain fishing), I'll just trade them for Xerneas and hope I get a good one, rinse and repeat for the others, etc.If you decide to fish on Route 8, DOnt use the Super Rod.
Use good rod instead in order to avoid qwilfish.
I dont say Qwilfish is useless though; You can still trade them for mewtwos on the gts. However, Starmie (about 40% with good rod, but only like maybe 10% with super) is an almost guaranteed Articuno.
That's assuming I actually get a shiny anytime soon...