IF you are more than 10 levels higher than the quests, the yellow ! does not appear over the NPC's head. It will appear on the zone map if you go to the setup in the top right corner of the map and make sure you do NOT have it set to "hide low level quests". You also MUST have done all the main quest line quests starting with Mysterious Torrog at Titan's Hill in Aotulia Volcano, through "Envoy of the Dragons" line and "Restore the Glory" line to the end of Nothern Janost Forest. Then you must complete the new quest line that starts there and goes to Land of Malevolence, Redhill Mountains, and Tergothen Bay to get transported to Ancient Kingdom of Rorazan.
IF you got portaled to Rorazan by a player, then you haven't finished the quest line.
Again- 1)Make sure you do the quests, and 2) If you are more than 10 levels higher, make sure you have the map marked to allow low level quests to show.
The NPC you are looking for is in Chrysalia at (49.8, 28.8) but the quest for the aroma assimilation potion is ONLY available if you have done ALL the main quest line up to that point.