@jwluoma, there is a net somwhere. Hit butterflies with it, and you'll catch them. Be carefull though, it degrades rather quickly, so you should use a different weapon to kill the emigo's.
@FeeOhNah, if you're using a set up that involves 3 ranged attackers, temporarily switch your weakest out for a random warrior at the last city. Helps with keeping them at bay.
Go go go!