Either the spawn locations are wrong or there needs to be a per-requisite to get them to spawn. the halloween event is on currently and i've gone from velia>heidel>calpheon to the areas pointed out for the lvl 10, 20, and 30 npcs with level 17, 22, and 33 respectively and none of the npc between 10pm and 7am spawned. Are they not in anymore with the various re-dos of the game?
Edit: The indeed did spawn in Loggia Farm fields. After 10pm on Oct 31/Nov 1st. The onew there seem to be lvl 10 as the are grey names to my lvl 26.
Spawn locations of the monsters are not stored in the game client. They're controlled from the server side. The ones we have here are taken from the quite old server data leak. They could have been changed. If you'll find this monster, please add it's new locations using the "Add location of this object" function on this page.