The Cards Tell the Tale (II): The Training Grounds, by Ben Peck
The original TRAINING GROUNDS set was released along the Diamond Edition base set, and was the LTP product for the Reign of Blood era, and depicted a battle between the Lion Clan and the Shadowlands forces. The product packaging (a sturdy two row box designed to hold around 800 cards) had a wraparound battle scene which was also used to illustrate several cards in the set.
Sadly it seems the full widescreen picture is nowhere to be found, except for the featured central part, with the two enemy leaders facing off, so well need to use our imagination to picture the full scene, as depicted...