I have a question about the MG15 card
Spirit Bonds. It says "Whenever a nontoken creature enters the battlefield under your control, you may pay 1 White. If you do, put a 1/1 white Spirit creature token with flying onto the battlefield".
No where on the card does it say you can only do it once i.e play a creature and create 5 spirits if you have the mana to do it. Cards like
Rootwalla from MG14 specifically say "Activate this ability only once per turn". Am I incorrect in reading this as being able to generate multiple spirits off of a single creature spell? If not, please cite the rule that disallows this.
Thank you.