This is the second time I hear about Thirsty Sword Lesbians here and I am still afraid to google it.

Is this serious or is it some sort of joke system?

Might work for Wizards but what about Sorcerers that Subtle Spell cast Power Word Kill?

Okay, I see how you would have to awkwardly keep your eyes open during kissing, but it would be possible.

“Geblockt” heißt dass der Katheder durch Formschluss Dichtigkeit herstellt, oder wird der irgendwie gesondert befestigt?

Sounds like Icewind Dale - Rime of the Frostmaiden to me.