The strategy that Li Yi had in mind was very simple. He would bring two healers into the party and request them to log out after they made their way inside the dungeon. Halfway through the battle, Li Yi would use Camouflage to flee from battle and would log out later on. The healers would then log back in so that they could replenish the party's HP.
Firelord's Instance Dungeon only allows two players to battle simultaneously, and when the party's numbers exceeded that value, the third player would be unable to enter the dungeon. The strategy that Li Yi devised had cleverly avoided the '2-player' limitation and in turn, allowed the party's numbers to grow.
Whether his plan would succeed, Li Yi was unsure. However, they would never know the answer if they never tried it out. Thus, he pulled Fire Ice and Little Elf from the Magical Realm over.