I can't say that this was my favorite as there are many things that aren't exactly explained. I am still ver confused about when Constance says that a Giftia can only live for 81,920 hours, which is approximately nine years. That does not explain why Constance, Isla and the other giftia appear to be older than nine years.
I wasn't very suprised by the ending either. Through out the series, they didn't actually show much about the wanderer, other than Michiru's Father and Marcia. Well those were the only two and they weren't really shown to "start acting on instinct and maybe even assault humans".