Right so Soul Mate's description reads as thus follows
Bind yourself to target character, copying any healing and Armour restoration that you receive to them. Clears Frozen, Stunned, Knocked Down and Petrified.
What has been discovered is that using soul bond on an undead enemy and using something like a huge heal potion does massive amounts of damage to them,this isn't mentioned in the description so I'm wondering if this intentional or an oversight?