I have a copy of Pokémon White 2 and I saw this video of someone catching Lugia in the Abyssal Ruins. I went to the last part of the Abyssal Ruins , but I couldn't catch Lugia even though I had Articuno, Zapdos, and Moltres. Is it because I already have Lugia, because it was present in my party, both, or some other reason?