ToME: the Tales of Maj'Eyal

The last room had Harkor'Zun. Killed the fragments and then the boss but the last orb wasn't activated. Checked the log and only five "XXX the Guardian" uniques were added. So, I'm guessing that killing Harkor'Zun should have activated the last orb but it didn't. If it makes any difference, I killed Harkor'Zun in a different part of the dungeon than in the original room where I found his fragments. So, can't open the final door, since the missing orb is the third step in the sequence.

I had a missing guardian in my last play-through too. I inspected the save file, and the guardian was supposedly in the correct spawn location in the upper right room, but, lo and behold, there was nothing there. So, this wasn't a case of a guardian hiding within a wall; it simply wasn't on the map where it was supposed to be.

I have the same problem in my current game.