Latias and Latios presented some very unique powers in the movie, such as sight-sharing, invisibility and shapeshifting. Latias commonly shapeshifts to appear the same as Bianca, and befriended Ash under her persona. She may have a crush on him as well, as was hinted in the movie, undoubtedly because he saved her from Annie and Oakley.
Latias is a very docile Pokémon. She appeared to dislike fighting and was easily scared off by any conflict or anything attempting to cause harm to her. She cared much for people and Pokémon close to her, including Ash, Latios, Bianca and Lorenzo. She was, however, shown to have a more mature side besides her childish and playful side, bravely joining her big brother to save Alto Mare from drowning.
Latias is one of the few Pokémon seen in the anime to have been shown to have a crush on a person, who, in Latias's case, is Ash. After saving Latias from Annie and Oakley, Latias was shown to have a complete trust on Ash, wanting to play with him all the time they spent together at the Secret Garden, and also being the one she sought for help when Latios was kidnapped.