But looking through the information in the CK, I can't find the scripts that define the spells' behaviors, and without finding those scripts, I can't figure out why the atronoch is getting cancelled, let alone stop it from happening with a non-conjuration spell.
I thought it would be a simple case of removing a trigger effect from cloak spells that must be cancelling the pet spells, but I can't check the scripts to find out if I can't locate them.