Pokémon Adventures, Vol. 28 by Hidenori Kusaka

Ruby and Sapphire are back! Professor Birch sends the fabulous duo to help Emerald find the Wish Pokémon Jirachi. But first there are high-pitched Pokémon battles to fight in the Battle Dome Tournament... Then Ruby discovers something surprising about Emerald's Sceptile, and everyone learns the true identity of their archnemesis, Guile Hideout. Now, who will catch Jirachi...?