These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Game Breaker: M0 in the world of magic. As it can erase any magic, it is described as "the strongest shield and the strongest halberd." When one learns to manipulate the shape of the M0 area of affect it becomes a very dangerous force.