Have you noticed that Legendary Pokemon in the anime are too hard to beat.
Tobias' Latios defeated Swellow with a single Luster Purge.
I accept Sceptile was already weak from battling Darkrai which made Sceptile's defeat understandable.
Tobias' Darkrai took a Megahorn and still remained standing, I accept that Dream Eater helped cure his health in later battles.
Drake's Dragonite has 10 moves and took 5 Pokemon to be beaten
Tyranitar hard to beat.
Cynthia's Garchomp as well