Warning! Spoilers ahead for Jujutsu Kaisen chapter 172!
Megumi Fushiguro still hasn't mastered Chimera Shadow Garden, but he just one-upped his opponent Reggie Star with this Domain Expansion by actually canceling it in Jujutsu Kaisen.
The ultra-powerful Domain Expansions are not only the supreme ability of jujutsu s, but also the most creative force in the manga that allows mangaka Gege Akutami to explore his obvious preference for in depth and complicated fighting sequences. Usually, once a sorcerer or another wielder of cursed energy creates a Domain Expansion, whatever happens within their advanced barrier becomes the foundation of their entire strategy going forward. But Megumi actually summoned the Chimera Shadow Garden in a pool-equipped gymnasium during his Culling game fight with Reggie Star, and based on how events transpire in chapter 172, he did this on purpose knowing that the shadows in his Domain Expansion emulate the feeling of water.
During the Culling game battle, the two jujutsu s struggle to keep themselves above Megumi's pool of shadows that is pulling them both down into its depths as a result of random large objects that Reggie has thrown into it through his receipt-based cursed energy. Reggie eventually gets pulled under, which he compares to drowning, but frees himself by summoning more objects with his receipts. And just when he summons a house and is about to crush his opponent, Megumi escapes into the shadows and cancels the Chimera Shadow Garden. This is important because the contracts Reggie created with these objects pull him down in the real world through the gymnasium floor and into the pool of actual water below. Because Reggie had already experienced Megumi's shadow pool, he first thinks he somehow got sucked back into the shadows before trying to get a handle of the situation in other ways. Even though Reggie eventually breaks the water's surface, he is still in rough shape because it took him awhile to understand how to acclimate to his new environment.
This isn't the first time that Megumi has tried to make the best of his incomplete Domain Expansion and use its limitations to his advantage. Earlier in his fight against Reggie, Megumi, being the genius that he is, chose the gym for his garden in part because it wouldn't allow him to complete his Domain Expansion, which, in turn, would affect the rules inside the Chimera Shadow Garden. This later confused Reggie enough to give Megumi a momentary advantage. Much earlier in the manga, Megumi summoned his garden within his enemy's more powerful Domain Expansion. However, instead of trying to get his barrier to win over his opponent's domain as is the usual practice in situations such as these, Megumi uses his to poke a hole in the other barrier to escape.
Megumi's battle against Reggie is therefore another example of how mangaka Gege Akutami finds creative ways to expand the original concept behind his Domain Expansions in Jujutsu Kaisen. It highlights Megumi's ability to quickly come up with a complex strategy in a matter of moments and use his Chimera Shadow Garden's inherent weaknesses as strengths. Interestingly, his comrade Yuji Itadori did something similar with his Divergent Fist by using its weakness to achieve the ever-elusive Black Flash attack. The difference, however, is that Yuji needed help in both realizing and achieving this new technique while Megumi's superior intellect has enabled him to do so on his own.
