Shades of Ianto by sarcasticchick
Jack/Ianto
series of 3 stories
https://archiveofourown.org/series/13812

Awesome series featuring Jack/Ianto and very much AU. The first two stories are great but the last one is just awesome. Ianto's character grows through the series as each disaster strengthens him for the final alien attacks. It will be his turn to carry on a legacy and he is the only one who can. You get to see who Jack started as when an early Jack before immortality is found in Torchwood 4 and Ianto convinces him to impersonate himself in order to help the moral of the team in the face of a possible invasion. There are character deaths and some that will surprise you. The affairs at Avalon will make or break Ianto and there are many times that he wishes for his Jack to come back. It takes a while to see that this Jack is still his Jack. These are the kind of stories you wished were produced for television. The author has created characters that will last long in memory. Simply amazing, you know when your holding your breath that the story is awesome.