Dear friend,
Using a monster with 2 pieces, brings Hipnotic into my mind: Armagon
Please read the source hiparma.qc (especially function: monster_armagon)
This might help you.
I think you should try this to better "link" them together:
self.trigger_field = body;
body.trigger_field = self;
or
self.trigger_field = newmis = spawn();
Maybe this helps you a little bit.
I hope you have a healthy and lucky new year 2013, Nahuel !
Seven