Monaka was initially introduced in "Dragon Ball Super" as the most powerful warrior Beerus ever met but this was later proven to be a lie and that Beerus only stated this to motivate Goku and Vegeta. However, the promo trailer for episode 42 showcases Monaka may be as powerful as hinted and that he will be going up against Son Goku.
Monaka has been silent during the tournament and it was revealed that he had passed out of nervousness and fear. His punch against Hit had no effect and he was revealed to be an amateur fighter who regularly worked as a delivery mailman. However, all that changes in the promo for episode 42, where he is shown fighting Goku in an even match.
Fans speculate that this means Monaka may have the necessary skills and training or the innate power to go up against Goku and Vegeta but is severely restricted due to this passive and shy nature. It is likely that Monaka may have discovered a means of overcoming this issue and may now have the will and ability to fight Goku.
This fight will occur during the celebration held by Universe 7's team following their victory in the recent tournament. Monaka arrives late and will challenge Goku to a battle, gratifying Goku's request to fight the warrior Beerus had boasted so much about.
According to a report from Ecumenical News, Cabba will also start training under Prince Vegeta. The clip from the trailer shows Cabba calling Vegeta his master, hinting that the Saiyans from different universes will be working and training together with the hopes of becoming even more powerful than Son Goku.
Unfortunately, it is undetermined at this point if the episode will see further development regarding the newly revived Earth of Universe 6, which was brought back when Beerus wished for its existence back when he used the Super Dragon Balls.
"Dragon Ball Super" episode 42 airs this May 8.