Crossing the bridge:
In labyrinth level is a "bridge". If you walk across it, you will be teleported to the pit below. To cross the bridge, do not walk over the markings or symbols on it.

Subversion without the spell or pipes:
Get a creature with a "crown" over their heads. If they attack an enemy creature of the same species they might be able to subvert it. This also works against illusions.

Destroying totems:
The following four spells can be used to destroy totems: Apocalypse, Lightning, Meteor Strike, and Storm.

Killing undead:
Summon a Unicorn. They have decent HP, mana cost and are effective against the undead. However, they are not very good against Champion Chaos and Vampires.