After defeating your rival at Mt. Moon and obtaining all 8 Kanto badges, you’ll meet your rival behind the shrine at the Dragon’s Den. Once you speak with him, Clair and Lance will stop by and request to battle. Your rival will team up with you during this battle against Clair and Lance. Dragonair will use Thunder Wave to paralyze the target and Dragon Rush for a 20% chance of making the target flinch. Kingdra will use Yawn to make the target fall asleep on the next turn and Dragonbreath for a 30% chance of paralyzing the target. Gyarados will use Dragon Dance to raise its stats and Waterfall for a 20% chance of making the target flinch. Charizard will use Air Slash for a 30% chance of making the target flinch and Flamethrower for a 30% chance of burning the target. One Dragonite will use Thunder for a 30% chance of paralyzing the target and the other one will use Draco Meteor to deal massive damage but sharply lower its Special Attack stat in the process. After the battle, Clair and Lance will leave. ... https://www.youtube.com/watch?v=Q2x4KXzynm4

Will uses Psychic type Pokémon. The first Xatu will use Confuse Ray to confuse the target and U-turn to switch out after causing damage. Jynx will use Lovely Kiss to put the target to sleep and Ice Punch for a 10% chance of freezing the target. Exeggutor will use Reflect to reduce damage from physical attacks for 5 turns and Hypnosis to put the target to sleep. Slowbro will use Amnesia to sharply raise its Special Defense stat and Water Pulse for a 20% chance of confusing the target. The other Xatu will use Ominous Wind for a 10% chance of raising all of its stats and Aerial Ace to strike without fail. Moves like Crunch and Shadow Ball work best for this battle. ... https://www.youtube.com/watch?v=E6GnT1JJT1k

Make your way through Area 5 of the White Treehollow and you’ll take on Elie, who is originally a Veteran Trainer. Claydol will use Rain Dance to summon rain for 5 turns and Explosion when running low on HP. When rain is in effect, Omastar will speed up with the Swift Swim ability and use Ancientpower to sometimes raise its stats. Jellicent holds a Choice Scarf to gain speed but only use one move and will use Water Spout to inflict big damage when full on HP. After the battle, you’ll unlock Area 6. ... https://www.youtube.com/watch?v=YZAwz8XI_YE

After completing Area 6 of the White Treehollow and you’ll take on Frederick, who is originally an Ace Trainer. Togekiss will use Air Slash to make targets flinch, Aura Sphere to strike without fail, and Extremespeed to strike first. Heracross holds a Flame Orb but getting the burn causes its Attack to go up with the Guts ability. It will use Night Slash for critical hits and Aerial Ace for never miss strikes. Rampardos holds a Choice Scarf to gain speed but can only use a single move. It will use Zen Headbutt to make targets flinch and Head Smash for massive damage but hurting itself as well. After the battle, you’ll unlock Area 7. ... https://www.youtube.com/watch?v=dI5OesMbsgo