Can a stronghold activate its special ability while pinned?
Under a special rule of the Activation section, it states: A Disk cannot be activated (move, cast, or use a Special Ability) if anothe disk is on top of it. Because of this rule, even Strongholds may not use their SA while pinned by another disk. Note: This also includes Items that may Activate independently from a disk it is attached to. While an attached Unit disk is pinned, the item on that disk may not Activate any of it’s SA’s since it is considered to be part of that unit disk.