The TRUTH about Noon and the Kyon-Shi
or
Don't change what you're doing, but know the REAL facts behind your actions...
(Pictures taken from Thorn Martin's Shining Force 3 Page)
The TRUTH about Noon...

When you reach the cursed village of Quonus, many hints tell you that the villagers have been turned into Kyon-Shi (zombies) and are being controlled by the Vandal.

In all the pages and FAQs I have visited, including
Thorn Martin's, there seems to be a general belief that, in order to get the so-called-secret character Noon, you must avoid killing ANY Kyon-Shi in the Quonus Graveyard.

Well, I have tried and killed a few Kyon-Shi (I couldn't kill them all because Kahn "zapped" a few with the Elbesem Orb...) and, after I defeated the Vandal, Noon was there waiting.  I talked to him and he joined the Force !

Then, I went to the village and less people were in the streets.  The Fairy acted as Priest because the Priest had passed away, and both ShopKeepers were absent (dead).  So I couldn't buy any weapon or item.

What happened ?  Simple : the Kyon-Shi were villagers, as you were warned, but not plain passersby !  The Priest and the ShopKeepers had also been turned into Kyon-Shi, and so had Noon !  So, Kahn must have "zapped" the Noon/Kyon-Shi with the Orb, allowing him to return to life after the Vandal was defeated.  The Priest/Kyon-Shi and ShopKeepers/Kyon-Shi were less fortunate, they were truly killed during the battle.

So, you should keep on avoiding killing Kyon-Shi, but not because it's a condition for Noon to join you;  avoid killing them because you don't know who they are, and you might end up killing Noon or the Priest or the ShopKeepers.  Some Kyon-Shi might be regular villagers, but don't take any chance, just don't kill any...
UPDATE !!!
I have completed my Who's Who
of the Kyon-Shi !!!
Click HERE !!!