A 3-hour cut of Legend exists on an internal StudioCanal server. It has never been released. Bits of it appear in the "Deleted Scenes" category. If you see a listing for "Legend: Extended Cut" – it is likely a fake.
If you prefer ownership over streaming, physical media offers superior bitrate and bonus features. Here is what you will find when of physical discs. Searching for- legend 2015 tom hardy in-All Cat...