When it comes to battle shonen anime, most fans of a given series will want to know which characters are the strongest. There are many ways to judge how powerful any given character is. At first, it will be about known feats of strength, speed, durability, etc. If those concepts become vague, fans can rely on how much they can destroy (buildings, mountains, planets, etc.). Of course, the most common way to judge which characters are the best is to see how they fare against each other in a straight fight. Unfortunately, writers sometimes leave the outcomes of these fights open to interpretation; this allows fans to believe their favorite character could win, depending on the circumstances. However, it's a monkey wrench for power scalers who want a straight answer.
Source：https://www.cbr.com/anime-sweat-scaling-acuracy/
