This quirk enables Takeshi to intoxicate himself, inducing a drunken state upon him. This particular quirk doesn't give rise to any enhancements of any aspect, it is practically the same as getting drunk through the normal means. That being said, many would view this as useless quirk seeing as it would provide more harm than good due to the mental power of the user being significantly weakened, an ability a hero needs to have at top notch at all times if possible.
However, Takeshi has managed to bring light to this quirk by learning to control his movements while intoxicated and in turn, unintentionally learning the strange yet effective Drunken Fist Style that turned his once useless quirk into a useful quirk.
Takeshi's power isn't only limited to himself. By having physical contact with another person, he can turn a once sober being into that of a drunken one, aiding him in battle especially if he is facing an opponent difficult to deal with.
Though Takeshi has the ability to intoxicate himself and other people, he does not have the ability to do the reverse, meaning that once the quirk is activated, it cannot be undone leaving the drunkard to rely on his/her own body to deal with it for them. This also heavily affects Takeshi himself as since he has no control on how long he will be drunk for, he is at a disadvantage if strategy will become a key part of the battle, making this quirk a double-edged sword for Takeshi.
That isn't the only downside to this quirk, since a drunken state is replicated upon use of this quirk, the same symptoms occur when being drunk, meaning that nausea can be felt during and immediately after prolonged use of the quirk,