Instructions
Complete all of the Village Elder quests. You will kill a large number of monsters along the way. Kill two of each type of monster to unlock the quest "A State of Crisis." Check the "Monster List" under "References" in the menu to see all monsters and how many of each type you've killed.
Travel to Area Three to begin "A State of Crisis" and start the battle with Shen Gaoren. Vary your attacks between his four legs and get all the legs to a dark red color from the damage. Activate the Dragonator by pressing "X" whenever Shen Gaoren opens his mouth. Attack his face whenever the damage to his legs is too much for him to stand. Keep varying your attacks until he is defeated, which will open up the quest "The Final Invitation."
Attack the first Rajang with sleep attacks, your Hi-Frost sword and the Akantor bow. Place large barrel bombs by Rajang whenever he falls asleep to deal heavy damage. Hit Rajang a few times in each attack and then move away, as his attacks are devastating and could kill your character quickly. Keep this up until both versions of Rajang are defeated to unlock his character.