[Angelox]

Here's a quick way (for PEQ database);
KOS no assist

UPDATE npc_types SET npc_faction_id=19471 WHERE (ID>=215000 AND ID<=215999);

or KOS with assist;

UPDATE npc_types SET npc_faction_id=19472 WHERE (ID>=215000 AND ID<=215999);

This will set KOS to every NPC in Plane of Air.
Here's how I did that;

the faction IDs are both KOS factions, one the mobs will assist on a long pull the other no. Since 215 is the zone number for PoAir , 215000-215999 are reserved for PoAir NPCs only. Look up the zone numbers for the other zones you want to set, and use the above as a template (replace the '215').

This is the quickest way, but it has draw backs- there are in invisible NPCs in PoAir that do not require KOS. Also , there could be other NPCs that may need to be indiff.
I look for bodytype or race AFTER I run the above querys;

UPDATE npc_types SET npc_faction_id=0 WHERE (ID>=215000 AND ID<=215999) AND race=127;

127 is invisible NPCs in the zone, not intended to be beating on you out of nowhere

Lets say you had merchants in the zone, so merchant class id number is 41;

UPDATE npc_types SET npc_faction_id=0 WHERE (ID>=215000 AND ID<=215999) AND class=41;

Eventually, after you've run these querys (make sure you restart the server for changes to take effect), You will have to go into the zone and make sure you didn't leave any stray unwanted KOS-converted mobs.

With this same example, you can quickly set up regular factions to whole zones. after you've made one for one NPC, you get the number and apply it with the querys above.