If anyone is familiar with this mod, I would greatly appreciate any feedback. I have been searching through forums (and the internet in general) for quite a while now and have gotten no where with this issue. This mod also seems to be discussed very rarely.

Everything works perfectly until I enter the throne room of Echo Cave. Manni is standing in front of his throne instead of seated and looks like an elf with horns instead of the demon face I have seen in pictures. He is also very easy to kill if I lure him from that area which I understand is not the case at all. The real problem is once I approach him and hit the barrier which throws me back (which is supposed to start the dialog) - he dies and I am permanently frozen and have to exit the game. I have tinkered with load order and also cannot find any reliable conflict info. It seems that this mod works for almost everyone. I run FCOM, Origins of the mages guild, the necromancer, etc, but have found nothing to indicate a problem.

Thank you in advance.

Are you using the OOO Version of the mod? If not, that could certainly be causing the conflict.

Magi - I appreciate any feedback at this point yes, I have both the regular .esp and the OOO.esp activated.

I have never used it but I just found this: http://www.gamespot.com/pc/rpg/theelderscrollsivoblivion/show_msgs.php?topic_id=m-1-51761896&pid=924363
Hope it can help.

I saw this as well and did deactivate Origins of the mages guild before I entered his throne room. Unfortunately, nothing changed. This is really frustrating, I am out of ideas.

There are quite a few mods that change Mannimarco. None of my own characters have had the brains to advance far enough in the Mages Guild to get the quest to confront him, so I haven't experienced this problem.
The only thing I can suggest it to look things over in TES4EDIT. Make sure all of your mods are loaded and check which mods affect Mannimarco and the cell in which he resides. That should at least give you a place to start.

Post your load order via Wrye Bash.