This is one of the ways to defeat lance.
My method only needs two [Level.100] Pokemon: Gengar、Gyarados
Gyarados Set:
Move: Dragon Dance、Ice Fang、Surf
Equipment: Never-Melt Ice //just make sure one shot, It will be need more [Dragon Dance] if you don't have
Team Leader is Gengar and also a pioneer of death.
Script:
1. Face to Dragonite, let Gengar trigger the Cursed Body. //It have 30% Chance. If not triggered, log out and again
2. Switch to Gyarados and use [Dragon Dance] 2-3 times If triggered.
3.Use [ice Fang] until battle end. //You can use [Dragon Dance] once if the opposite side gets Frozen