We don't actually have a Mitigator at Stec Records but you can find the user's guide on our page for it
I don't recall support for a powered midi cable but they made them for a few years so it's possible that they did at one point. I'm pretty sure it gets power from an external power supply (wall wart, etc..). These also get modified all the time so it wouldn't surprise me to see a powered-cable-mod for the Mitigator out there.
The Voodoo Lab GCX supports midi so the Mitigator can control it. Most of the meat and potatoes things that people do with midi can be done with the Mitigator including program changes, controllers and sysex. Even more advanced stuff such as Show Control (lighting) can probably be handled, though the set up would take some time and skill but the Mitigator is perfect for controlling devices like the GCX.