Seadra was Mandi's second choice of Pokémon after his Exeguttor was beaten by Ash's Krabby which, after the victory had just evolved into Kingler.
Seadra charged quickly towards Kingler whose attempted to counter with a water gun was dodged. As Seadra got closer, Kingler changed its attack to a Bubble and managed to send Seadra skywards as it could not dodge and maneuver around the attacks. Ash ordered Kingler to use a crabhammer on the airbourne Seadra and knocked its back into the water, eliminating it from the battle in the Process.
A clearly annoyed Mandi had to once again calm himself before choosing his final Pokémon, a Golbat