Rouga and Cerberus. When they first met, the battle lasted for 3 days, and left multiple scars on their bodies.
Ability / Effect:
[Counter] Choose a monster on your field, and for this turn, increase its power or defense by the power of a 《Weapon》 on your field, and it gets [Counterattack]! ([Counterattack]: If this monster is not destroyed after an attack, choose a monster that attacked with defense less than or equal to this monster's power, and destroy it.)