I should create an archive of Dives on the Wiki or something.
Here is what I believe to be my largest Dive to date, in terms of number of rolls:
http://www.bay12forums.com/smf/index.php?topic=171120.msg7899435#msg7899435two material spheres, 21 Nerve rolls, + the final Nerve roll. This was to restore my dream robot body to wholeness after I got eaten by a giant bird made of buildings. This Dive succeeded.
HEre is an example of a strong effect with a relatively small number of rolls:
http://www.bay12forums.com/smf/index.php?topic=171120.msg7915428#msg7915428that was to put another character's head back together after it had been obliterated by a head-sized arrow. This Dive succeeded. I was already under the effect of a previously failed Final Nerve roll at the time.
I believe AsHul has failed three final nerve rolls: One got hm possessed by an entity from Balaram. One caused him to collapse into a ball of whininess. and i forget what the third did, if it happened.
Other Divers have likewise failed nerve rolls, one getting possessed by creatures from Es, then having their skin peel off and their body become extremely flexible and wobbly, then finally being converted into a dimensional gate and morbid art installation.
So, as you can see, failing the final Nerve roll has quite diverse repercussions.