Host demanded additional payment outside of app, which is against terms of service. After being reminded of this, they made a resolution center request within Airbnb to pay them 150 euros before the stay had even began. They tried to say it was a 'safety deposit', but that's not how safety deposits work, and they already had one set up with Airbnb in any case. This was just an attempt to demand a second deposit.
After being called out on all this and me being advised not to pay by Airbnb staff, they simply went silent on the day of my checkin, leaving me without accomodation. Thankfully a nearby host kindly let me book with the help of Airbnb staff. Overall, don't rely on these guys. Book somewhere else.