A man, a plan:
Mekaniker: HQ is always fortified if you have at least 8 defenders; or if you roll doubles on defense the territory cannot be attacked any more that turn.(or is it until your turn?)
It's only until the end of that turn, and only for double 6s.
The first power doesn't have the "at least 8 defenders" restriction, it’s always active (but only for their own HQ).
Spoiler (click to reveal)