I really did like this and even more so because it was unusual. I have a bit of a kink for anything new or different. (Which is SO *unusual* because everything has so been DONE to death over all the years.)
With Lucius I picture him being fascinated by this brilliant kid who gets sorted into Slytherin and slowly becoming more and more drawn to him as someone totally different from everyone else he know. Smarter, more real, more immediate, more raw, and under the defenses, more broken and lost. I think somehow that neediness would call out to Lucius while the brilliance would fascinate him. I think Lucius grew up surrounded by beauty but probably a lot of illusion and falsity. That high brow fake nonsense. And even if Severus isn't that good looking I still think he's got a presence and power to him which holds an allure.
And Lucius' beauty, wealth, connections, intelligence, power, pureblooded-ness,and the "normalcy" of his family would fascinate Severus.