I think it is one of his illusion to bring out berry's full potential that he talked about in this chapter (full potential as in when MC is about to die or his loved one is about to die he suddenly gains more power and saves the day)
when he fights the Speedforce its ask why he did all this to it and Mc's awnser is i didnt do this to you you did this to yourself by denying my what i asked for first nicely perhaps you took that as weakness and thus doomed many of your speedsers and their allies all becouse you denyed me