Hell, I have seen Dream_walker kill a N'iax with just the Destroyer and that ult along with a few Arcane Orb shots. The destroyer's strong hand was designed for ints to take down those pesky late strength heroes. Cause face it, you can do 300+ damage per hit with the Orb because of your mana - then end the guy's life with a skill that can do severe damage just because strength heroes have lower int.
I also do believe it also takes into consideration all int+ items. I guess soon, it will be able to use "Aghanims".