Knight Commander Derik, Ricarten Town
Knight Commander Derik is located south of Blacksmith Goden near the stairs going to Skill Master Verkan at Ricarten Town. If you are taking up the Test of Kingdom sidequest, you better ask him first.

Newter the Sage, Pillai Town
Newter the Sage can warp you at the entrance of different dungeons like the Mushroom Cave, Beehive Cave, Ancient Dungeon, and Railway of Chaos. He is Located near the Jail Guard at Pillai Town.

Royal Mage Ray, Pillai Town
If you are level 90 and above and want to take the Bitter Ordeal sidequest, you better talk to this NPC. He is located between the Jail Guard and Academia De Witchcraft Raymon at Pillai Town.