Lucy used her Seviper in the Battle Frontier's opening ceremony against an Electrode and a Swalot while it was teaming with Spenser's Crobat. Seviper used Poison Tail on Electrode while Crobat used Poison Fang on Electrode as well, badly damaging Electrode. Swalot used Yawn and Seviper fell asleep. While Seviper was asleep, Swalot used Hyper Beam on Seviper. Hyper Beam however only hit Seviper's skin and Lucy revealed that Seviper was already awake due to its Shed Skin ability. Seviper then used Dig on Swalot, knocking Swalot out. Lucy later used Seviper to wrap itself around Emerald when he crashed into the opening ceremony, so that he couldn't escape.
Seviper was around Lucy, who decided to take on Emerald's challenge. Just as Emerald was binded to the Battle Pike with Tucker and Brandon, Lucy's Seviper used Poison Tail to free them. Eventually, Emerald faced Lucy in the battle and had Blissey use Seismic Toss on Seviper. Though Blissey succeeded in the attack, Seviper's venom spouted out on Blissey, badly poisoning it. Seviper was swapped out with a Shuckle, which made Blissey harder to fight against it. With Milotic and Shuckle defeated, Lucy sent Seviper back in, who poisoned Rapidash With Giga Drain, Seviper defeated Rapidash and faced Emerald's Blissey. Seviper attempted to use Crunch, but was hit by its Seismic Toss. Despite this, Seviper managed to defeat Blissey, but not before the latter healed Rapidash with Softboiled and Heal Pulse. This made Rapidash healthy and defeated Seviper with Flame Wheel, earning Emerald the victory.
Seviper was with Lucy, who tended to Noland in the hospital. Lucy and Seviper faced Emerald, as the Frontier Brains suspected him to be Noland's attacker, who stole Sceptile from the storage system. While facing Guile, Lucy had Seviper use Sludge Bomb. However, Guile waved his sword and repelled all attacks away from the Frontier Brains.
Later on, Seviper was near Lucy when she talked to Scott about Guile. Since a lot of visitors arrived to the Battle Dome, Lucy sent Seviper and Milotic to help her and Greta usher the people to their seats. Due to Guile sending the Battle Factory's rental Pokémon out to cause trouble, Lucy sent Seviper to handle the situation. However, they faced the sea Kyogre that Jirachi created from Guile's wish. Thus, the Frontier Brains tried to calm down the rental Pokémon, while also dealing with the flood. Unfortunately, the sea Kyogre swept them away with the force of the ocean.
Lucy's Seviper was used to launch an attack against the meteorite.
|Poison Tail||Swanky Showdown with Swalot|
|Dig||Swanky Showdown with Swalot|
|Poison Fang||Just My Luck... Shuckle|
|Giga Drain||Just My Luck... Shuckle|
|Crunch||Just My Luck... Shuckle|
|Swagger||Just My Luck... Shuckle*|
|Sludge Bomb||Skirting Around Surskit I|
|+ indicates this Pokémon used this move recently.*|
- indicates this Pokémon normally can't use this move.
- ^ EM008: Just My Luck... Shuckle, Seviper is shown to be a female in the statistics
- ^ EM002: Swanky Showdown with Swalot
- ^ EM003: Interesting Interactions Involving Illumise
- ^ EM005: Gotcha Where I Wantcha, Glalie
- ^ EM006: As Luck Would Have It, Kirlia
- ^ EM007: Moving Past Milotic
- ^ EM008: Just My Luck... Shuckle
- ^ EM010: Chipping Away at Regirock
- ^ EM011: You Need to Chill Out, Regice
- ^ EM013: Skirting Around Surskit I
- ^ EM015: Sneaky Like Shedinja I
- ^ EM021: A Cheeky Charizard Change-Up I
- ^ EM024: Lemme at 'Em, Lapras!
- ^ EM026: The Final Battle I
- ^ EM027: The Final Battle II
- ^ EM031: The Final Battle VI
- ^ ORAS017: Omega Alpha Adventure 16
- ^ ORAS022: Omega Alpha Adventure 21