The Black Lion Sticker set was given away as a purchase bonus when buying 2,000 yen or more of Zoids Wild kits at qualifying retailers. This bonus campaign started on March 3rd 2019 and most likely ran until supplies lasted.
One thing I’ve been personally doing with my sticker variant Ligers is putting a different set of caps on most of them. For this one I went with the Death Metal black caps, also from another bonus campaign.
Despite it being a sales bonus item, this sticker set quickly went up in price and started to become harder to come by as time went on. Unlike the Blue Flame Sticker set, original Blue and Black bonus caps and the Wild Liger Blue Thunder Version, all which are extremely easy to find as of this writing (9/2/19).
Sticker and Instructions Scans:
For the other (many) Wild Liger variants, click below. Getting this page started.