This is an ultimate rare animal, and one tough animal to defeat, even sometimes using ultimate will not work. Use a gold or strong animals. For gold, use one of the machine animals and use a powerful strong card. Before you start, pick Strong when choosing your opponent's strength. If you play Version 12, pick normal. Also for Version 12, I recommend you use the ultimate Cobalt Shark and equip it with the gold 335 Strong card and the 5200 Alien Egg Gold miracle. For Version 11, I recommend you use Machine Shark - HG and then Equip the strong card with the 445 and Aligned Planets or Alien Egg gold for Version 12. Get ready to battle! At Round 1 be sure you already save all of your health for sure and for the next round, use miracle attack or best attack to win. Now we will go to the final round! Pick "Challenge Machine Lion -HGX" and get prepared!
First trick is that sometimes this boss will use 20 in the attack slot, so you can get more chances to win. After you attacked, the next attack will start. At your attack slot you must stop at your Miracle Attack and win the slot battle. If you lose, take part in tapping the green and yellow buttons until you got Focus guard. Basically the focus guard can be done easily in this boss's attack which looks like the best attack of Gray Wolf. Now, win the attack slot and deal a damage to the boss, when it's health reaches 30% or less, he will use an ability to make it's attack damage much bigger than before while locking your animal out. Time to get aggressive! If you trigger your best attack or miracle attack with a doubling, you will be sure to strike this enemy off.