Davor the Unkillable's page

This is probably a dumb question, but I've spent half an hour on Google and can't figure it out. I'm building a sword binder as a baddie and was wondering if he gets multiple attacks with his sword if the spell targets multiple people/has multiple rays. For instance, if he cast scorching ray he would have 2 rays at 10th level. Would he then get to attack with his sword twice at the cost of one standard action? Or would one of the attacks get cancelled since the ability describes it as one attack?

In my homebrew campaign the party has run afoul of the local thieves guild. The boss of the guild has an artifact which allows him unlimited invisibility and intangibility (I know it's kind of OP, but there are 12 of the artifacts and they all do something ridiculous). I'm having trouble coming up with a build and strategy that is not either a pushover or impossibly annoying. He should be around level 10 and will most likely be on the losing side of the action economy. Any ideas?