If you just want to "get it over with";
I did it with just henchmen as a mesmer in 55 minutes using that method :
1. Kill the Tengu Stars first, they don't respawn.
2. Keep a tight control the henchmen with flags so they don't rush ahead of you and agro the Celestials. Keep them far from the Celestials.
3. Use a longbow (even if you are not a ranger) to attack the stars and pull them to you group of henchmen. DO NOT RELEASE THE HENCHMEN'S FLAG.
4. Once the Stars are killed and you have a clear path from Celestial to Celestial, kill the Kirin first and the essences will spawn (they are NOT healers but smithing monk and not that good at it so no big deal there). When going around a Celestial to go to the next area, use flags again to keep the henchemen in a tight leach.
5. For the other two Celestials, kill the essences around it the same way as the Stars and then the Celestial, one by one. Remember that they will respawn after a while so there is no going back ! Then go do the Turtle, the Dragon and at last the Phoenix (because a large group of mesmers casting "Image of Remorse" is a bad thing ! LOL) The last Celestial you can go for it without killing the essences around it as killing it end the mission.
Note: Bring couples of keys for the chests in the area !
That way you gonna be able to complete Nahpui Quarter and end up in Senji's Corner to go on to Tannakai Temple and the rest of the storyline.