My friend and I stayed at the apartment for two nights. Since Lukas wasn't in Athens, his cousin Fedros took care of us. He came to pick us up at the station, took us to the apartment, and explained everything that we needed to know. On the third day, we needed to leave very early in the morning, but Fedros came right on time to get the keys. I had to take the ferry from rafina port, and the there was a bus from victoria station to rafina. How convenient!
Before I went to Athens, I made a big request to Lukas asking if I could leave my luggage with his cousin while I travel around the other islands in Greece. Lukas replied promptly, and also told Fedros about the situation. Fedros was very nice and kept my luggage for four nights, and even brought it to the victoria station when I got back to Athens.
I don't think I could've wished for a better host. Lukas and Fedros, thank you for everything! Thanks to the both of you, we had a really great time in Athens!