In the creation history of the Alpha Legion, some names were REDACTED 3 times. One suggest us about the failed Legion created from the source of potentially tainted population. Other suggest the Emperor had wipe them as a failed experiment, and dont didn't pass the proto legion state (the time when the Legion grows from the 1000-2000 proto marines and expand to a full grow legion of tens of thousands). And other suggest that like the XX legion, one of the destroyed legions have something to do with the Legion Custodes experiment and the Labrik Polaris incident. {{Fn|29}}