This is the first Legion book that I've read. The only other story was in a superman the man of steel book, I didn't pay that much attention to. I Only know of the legion tough mentions on twitter an the TV show(never got into it).So I was interested in this book.
The story is a about the future, more accurate, the 31st century. Darkseid is now just a stone fossil, barely alive. But you know Darksied, he wants to control the universe, even in rock from. First his disciples (one a very dark Orion) steal a teen Clark Kent from the past, thus screwing up the timeline.They also screw up the timeline by bring a young Darksied to the future, forcing the Legion to fight side by side along the young Darksied.
The story was so so, it started with the usual "new recruits to out team" story, which done right can be be good. Somehow, they find superboy is a stargate, not tell how he got there and why.The writers fail ti show the complete rehab of superboy, which I wanted more of. Also the change of superboy's uniform from the black tee and jeans (which I like) to a muscle reducing superman uniform which just looks wrong on him should not have been done. One major problem was the cut in to the story with a reporter interviewing the members of the legion.It should have been at the start. At least the fight at the end was good.
The Legion Foundations is a read if you want to see what the Legion is like. I would not suggest this as a must read. If the story has done right, it would have been a good read.