The Interview
There were three possible situations here unfolding for Sebastian:
He could say his real name, but that would make the Four Sacred Clans aware of the fact he, Sebastian Wells, awakened. That meant the past would repeat itself, with those motherfuckers likely going to search for him and his family to get rid of them.
Sebastian had already taken this route in the past. He had been naïve back then, thinking the Four Sacred Clans wouldn't have problems with him becoming a Thespian, and for sure not moving to kill him and his family.
But he wasn't naïve anymore. He would not repeat the same mistake.
The second alternative was using his fake name, the one he got from The Hound back in the black market.
But even this had problems. The most important one was that by doing so, he would leave a trace to where his mother and brother were.