So far, Chainsaw Man's return with Part 2 has been very unique. Tatsuki Fujimoto surprised readers by creating a new context, but also completely new characters that will have a major impact on the plot. There are still doubts and questions about what will happen also related to Denji.
Yes, because the protagonist did not appear in Chainsaw Man 98 and 99, the first two chapters of this second part. Fujimoto has not yet shown its protagonist except through posters and TV shows, so far from the main cartoons. So what role will Denji play in Chainsaw Man Part 2??
It seems that the mangaka decided to give time to the new character Asa Mitaka who is possessed by the war devil. Considering that the latter could be the real villain of the second part, that's possible at the moment Denji will pause to build and improve the character of these new characters.
However, it's unlikely that Denji and the Chainsaw Man will be on hiatus for too longand will certainly be starring again in a few more volumes once the introductory thread of Asa Mitaka and the Devil's War is finished.