Temple Ruins lich in chamber next to the 'lava floor' room

[Lemernis]

Yes, I think the wardstone allows the party to pass by the dragon without him turning hostile. When I had Yoshi scout (while stealthed, though the stealth may have been irrelevant given the wardstone) the dragon ignored him. Yoshimo was then able to lay traps (i.e., the dragon does not attack as he does so). The party then buffed up. Afterward, as soon as the dragon sights them he becomes instantly hostile.

 

If the party does not lay traps/buff they can walk right by the dragon, and the dragon will remain neutral as long as no one speaks with him. However, if the party does speak with the dragon that apparently breaks the wardstone's effect. The dragon will then turn hostile.