Warning: the following article contains spoilers for Jujutsu Kaisen Chapter 173 "Tokyo No. 1 Colony, Part 13," by Gege Akutami, John Werry, and Snir Aharon, available in English from Viz Media.
Satoru Gojo's Limitless is by far the most powerful Cursed Technique seen in Jujutsu Kaisen so far. Toji Fushiguro was the only character known to have fought effectively against Gojo's technique up to this point and he was a special case. Toji didn't have a Cursed Technique but he was blessed with incredible physical abilities due to his Heavenly Restriction. Moreover, he was in possession of the Inverted Spear of Heaven, a Cursed Tool that could nullify any Cursed Technique on contact.
Chapter 173 introduced a Cursed Technique that's so powerful that it's apparently effective even against Gojo's Limitless. The newly revealed technique in question belonged to Fumihiko Takaba. Takaba hadn't been seen since he ran off to fight Hazenoki (Reggie's ally) in Chapter 169 after teaming up with Megumi. That was a huge help to Megumi since fighting Reggie alone was extremely difficult. He displayed surprisingly impressive fighting skills that made Megumi admit he was glad they aren't enemies.
The Limitless technique brings forth the concept of "infinity" into reality. It allows the user to manipulate and distort space at will. Takaba's Cursed Technique which is fittingly named 'Comedian,' also has to do with reality manipulation, but on a much larger scale. When he comes up with something that he's certain will be funny, it becomes reality. In other words, he can seemingly make any ridiculous thing he thinks would be a good joke into reality.
This likely explains his shockingly amazing fighting prowess. He showed off quite a few unbelievable skills in his fight against Hazenoki, including superhuman speed and strength. He moved so fast that it could easily be mistaken for teleportation. Now that his reality-altering Cursed Technique was revealed, it wouldn't be surprising if he actually was teleporting. He also managed to send Hazenoki flying through buildings with his hits while seemingly being unaffected by the attacks he himself was hit by.
Hazenoki was so frustrated and confused by all this that he gave up trying to beat Takaba and just moved on. The comedian even suddenly became covered in sauce to make himself slippery at one point. The most plausible explanation for all this is that it's entirely due to Takaba's technique. It's not that he's actually that fast or strong. He thinks of those as being funny scenarios as he's fighting which results in them becoming reality. It also explains his apparent healing. He probably imagines that it's funny getting hit by countless attacks and turning out to be completely fine.
The craziest thing about Takaba having such an insanely powerful technique is the fact he knows absolutely nothing about it. It seems he's been using it subconsciously this whole time. He definitely realized that he has some special power but he has no clue about the specifics. Nonetheless, Yuji and his allies are lucky he's not a villain and doesn't even wanna kill anybody. His technique makes him near-invincible in the same way Gojo is.
Takaba could prove to be a real challenge for Gojo in a fight if he learned the details about his technique. Especially if Gojo has to figure it out on his own. He simply has to imagine that the Limitless technique not being effective against him or Gojo not being able to use it while they fight is funny. However, it's unclear if Takaba's technique has any significant rules or limits. Regardless, the only thing stopping him from being the most dangerous threat in the Culling Game is his ignorance.
