That was Beldam's mistake leaving Vivian alone with finding the bomb; she self-reflected hard enough after helping Mario - unknowingly until confronting Doopliss again at Creepy Steeple that the shadow she was aiding in returning his body and identity was the enemy she and her sisters were at odds with, yet returned to be with him - finally having had enough of her Big Sister Bullying/Transphobic Mierda dumped on her. Vivian didn't deserve this maltreatment, so as such Beldam's prime mistake in her sister's betrayal was leaving her alone with finding the bomb instead of finding it together. MUCH convenient when you look into the Four Heroes tale in Rougeport's history in that among the four, a Boo who was in allegiance with the Shadow Queen defected to side with the heroes - particularly because of a Brave Koopa's strong soul having got her attention and caused her cold disposition to melt; this case is a strong parallel since the Shadow Sirens/The Three Shadows were part of the same side, but still only one of them defected by a hero's positive trait; it is Beldam who is at fault for Vivian's defection to siding with Mario - as his kindness was what ultimately won Vivian's friendship and trust - all no thanks to her constant gaslighting/transphobic sibling bullying. It's all well dandy to play though the game again through the remake and I still have the original game even now and still have my fondest memories of the gameplay and the story. But I've hardly played the latter nowadays, and I haven't gotten to the superbosses yet as I had just cleared the remake's campaign a few weeks ago. But I'll get there eventually.
The game is running with a 60 Frame patch. Originally I was going to do this playthrough at its native 30 frame cap. Shortly before the release of the game (by one day) there had been videos going around with this game running at 60 on emulators. I think you can even run this patch(mod) on a v1 switch even. In the next Episode of this towards the end I run into the game running slow for the first time. (This is when you come across the ship of Cortez) this is the first time I see the game run slow with this patch enabled. Even if I wanted to play the entire game at its native 30 fame cap it’s hard to do that now. They did a really good job with this.