>... Barkhorn's ability to use Hammer's striker unit.
The ability isn't all that weird. Any witch could use it.
Surviving the experience with even a shred of magical power, on the other hand, is a bit of a challenge. Let's hope Trude's time in Zauberschule gives her a backup option.
(I'm inclined to think that von Hammer's interest in Zauberschule is based in part on her suspicion that she's tapped into the Force to keep going, and she's trying to find some way to confirm or deny the hypothesis.)