Siebold is a character appearing in Mega Evolution Special I, who is a member of the Elite Four in the Kalos region.
Siebold is very tall and slender, with pale white skin. He has light flaxen hair that curls around his head in graceful ripples. He possesses penetrating catlike eyes that are a deep sapphire-blue colour. Siebold wears a very regal uniform; his cloak-like garments are mostly pure white, mixed with some blue patterns, similar to a garment worn by royalty. The front of his shirt resembles a chef's garb, with four large white buttons, but it is merged with medieval-looking apron-like vestments, and is also slightly reminiscent to the uniform of a sailor. His uniform is high-collared, and his collar is rippled around the edges, like a scallop shell, and coloured blue and white,. He wears a unique cerulean blue striped cravat (a flowing, wispy tie) with a Key Stone, the Mega Buckle. His shoes are white with blue trim.
Siebold is a master chef, who considers battles as an art. Siebold sometimes uses chef expressions during the battle, claiming "the main dish" as the pinnacle of the battle.
Mega Evolution Acts
Siebold's butler came in and said that there was a guest asking for Siebold when he was working in his restaurant. Siebold went outside and greeted the guest who asked for him and it was revealed that the guest was Alain. Alain asked him for an 'unofficial menu' and Siebold saw his Mega Stone, understanding what Alain meant. Mairin appeared as well and while she was scolding Alain for not taking her, she was surprised to see Siebold. Siebold accepted Alain's 'menu' and they went to the battlefield. Siebold was surprised that Alain used a Charizard against his Blastoise since Charizard would be in a disadvantage. Alain stated that it didn't really matter and Sievold appreciated it, seeing the battle as an art. After Mega Charizard X countered several attacks from Blastoise, he Mega Evolved his Blastoise into Mega Blastoise. Both Mega Pokémon gave each other a tough battle and in the end, Mega Blastoise came out victory. Siebold still praised Alain for handling the battle well and said that even with a type disadvantage, Mega Charizard X was almost able to corner Mega Blastoise.
Season 19: XYZ
Lysandre explained to Alain all the battles he had with trainers that wielded Mega Evolution was to collect the energy required to control Zygarde.