While activated Inverse makes it so all attacks against the user are reversed in terms of damage. Strong blows become weak and weak ones become strong while the technique is activated.
If Inverse's effect were literal, something as weak as air resistance could kill the user while the technique was active. As such, there is a maximum and minimum limit to its conditions.
There are several weaknesses that user may not be able to compensate for. They're at a disadvantage against complicated techniques such as the Limitless. Additionally, the technique can be countered if the user's enemies hit them with a strong attack and a weak one at the same time.
Awasaka uses this technique without divulging it, making it appear as if he was nigh-invulnerable to all Megumi and Yuji's attacks during their fight. They wasted many attacks trying to understand how it was that Awasaka was so tough.
Attacks from Megumi's shikigami, Yuji's superhuman punches, and sword slashes were all completely nullified. Awasaka even survived a forty-story drop straight to the ground from the top of Shibuya Tower. Heavy things such as cars and the weight of Max Elephant crashing on top of him weren't difficult for the curse user to deal with either.
Megumi and Yuji ultimately countered Awasaka's technique by relentlessly attacking and mixing in weaker attacks with the strong ones. Awasaka was ready to counter a full-powered punch from Yuji, but activating Inverse made a simultaneous attack from a weak Toad shikigami a powerful blow to his organs. Yuji defeated Awasaka by adjusting the power of his swing at the last moment to trick his opponent and use Inverse to make a weak punch extremely strong.