Here is the scene where Articuno, Zapdos and Moltres fighting each other and Tino summons Lugia to stop the fight in War of the Apocalypse.
(Then they look up seeing three Legendary Birds fight each other)
Flain: And Moltres!
Rex Owen: Three Legendary Birds Pokémon!
Tino Tonitini: Stop fighting!
Sunset Shimmer: Tino, look out!
(Sunset Shimmer grabs Tino away from the attacks)
Ash Ketchum: Now what do we do?
Tino Tonitini: Let me handle this.
(He closes his eyes as we see the image of a mysterious Legendary Pokemon with it's eyes glowing light blue)
Tino Tonitini: Beast of the sea. We need you!
(Then a tornado made of water pops out and it hits the Three Bird Trio as the water clears out it is reveal to be Lugia)
Carver Descartes: No way!
Lor McQuarrie: It's...
Ash Ketchum: Lugia!
(Lugia looks at the Legendary Bird Trio and let's out a whale sound)
Max Taylor: Cool!
Rod: Lugia will stop those bird trio from fighting.
(Then Lugia fights the 3 Legendary Bird Trio in the sky)
Yoshi: Wow, now that is awesome!
Donkey Kong: Yeah, i know.