Had a possible idea if chainsaw feels that they wont be able to work on this and have to end the game sooner that the MC has a possibility of still getting all the legends in the series. It would be that as the MC is going back to Maples lab to finish the journey he get intercepted by the rest of the legends for some reason. This would only happen if the MC has collected ALL the legends so far including subs and mythical and met with all the women so far as well.
An example would be just after completing Gen 6 and the MC is going back. Gen 7 would have been the place to meet Team Rainbow so instead they intercept his boat to get his legends if he so far has all other legends from Gen 1-6. So Team Rainbow would have captured all the legends of Gen 7,8 and 9 since they would know there locations from other dimensions. They would have a mind control machine to control the legends and the MC would need to destroy it to free them. On his last attack on the machine it somehow sends his charm ability effect to the legends before being destroyed. This would not force the legends to like him but the legends have already heard about him a lot and looked forward to meeting him to judge if the want to join him but got beaten by team rainbow and brought along to him and are now free so they join him.
If Chainsaw is able to keep working on the game and does not use this then that would be excellent.