Looks like I really have a Super Luck ability
Soft resetted together with Kaworu to get shiny legendaries in Black2 (Cresselia) / White2 (Latias) and approximately after 12 hours of soft resetting we got BOTH. They appeared one after another within a hour or so. First was Cresselia, second Latias.
And that’s not all - we started to soft reset second Cresselia at White 2 after Latias capture and she appeared too. NO ANY CHEATS, it’s absolutely legit SR shinies. I don’t know how it’s even possible, but I’m uber happy now 

By the way, second shiny Cresselia will be up for trade when pokebank/poketransfer will be released. I will not trade her in gen5. At first I planned to SR only one shiny Cresselia for trades, but when she appeared, I realised I don’t want to get rid of her, she’s so freaking beautiful, I have no words!

By the way, synchronize ability Umbreon worked on both and gave them modest natures, but failed on Latias (she’s Careful, but who cares, she’s yellow!)