Ha! Great question!
We just created a new FAQ about to go up online to address this question, and also adjusted the rules for the next printing of Mage Wars.
As always, we want Mage wars to play as realistically as possible, unless it adds unnecessary complication.
Here is the clarification: If a creature wants to attack itself, or an object attached to itself (such as Tanglevine), it may ignore guards.
Hope that helps and sorry for any confusion!