>>/3812/
I will agree with you that it looks really weird that she would play with Masamune all of a sudden. It's not like she played a ton with him before. And she decides to play a completely new hero right along with it.
But, the one thing that makes no sense to me, is the "why". If Bonbi isn't familiar with MOBAs and obviously isn't very good at the game, leveling up her account, so she can play ranked, isn't going to help anything at all.
It makes much more sense that anonce no longer plays with them, so that they hopefully get matched against weaker opponents and won't get crushed as hard. That would also explain the "go from brain-dead to competent", because now Bonbi is playing against enemies that are closer to her actual skill level and she doesn't look as bad in comparison.