Luna held the shield as ponies piled through the hole she'd made, shrinking it slowly as ponies left to concentrate it's strength as the Mareitanians stepped up their efforts to break the shield down. It took a few minutes to get everypony out, and by the time Luna was able to follow the courtyard was filling with soldiers. To stop them following she tore at the building with her magic, filling the hole with enough rubble to put the soldiers off from following the same way as she turned and sprinted.