If it were 2 accounts, I would also agree. But when there are dozens of such accounts, it is no longer a straw. Can you explain how from July 1 to August 17, 60 accounts suddenly appeared on the forum who write the same, write in Chinese or are interested in Chinese topics?
I'm not doubting that some/many/all of those accounts are owned by the same person(s), I just not convinced RainbowKun has anything to do with it.
For more proof, check out RainbowKun and kxwhalexk's posting style. This is the clearest example of the fact that these accounts were managed by one person. There are so many similarities that you have to be blind to claim that this is written by two different people.
Clearly I'm not the only one "being blind": moderators haven't banned him on ban evasion yet.
Speaking of kxwhalexk, is
this his Twitter handle?

Because that address has been used on the forum before:
In the next two to three months, I will officially launch a blockchain DAO project, which I call Rainbow City.
This looks quite convincing indeed.