The thing about Vox Machina is that they are a frat party that woke up one morning after a drunken bender and decided to hunt down the serial killers who murdered their friend's family. One thing happened after another and they ended up taking out some very bad individuals in power at great personal cost, which propelled them to mythic status.
But fundamentally, VM is a college frat party that got impossibly attached to each other in the process of trying to do some good.
The Mighty Nein are a group of confrontational, distrustful pariahs who are vulnerable to outside influences that try to manipulate them into a villain arc. But after they completed trauma dumping and crisis bonding, they closed ranks and ground every single one of their personal demons to smithereens.
In essence, the MN are an exclusive, protective battle blender that only saves the world in order to save each other.
Bells Hells are defined by extreme stress. VM was trying to save the world, and the MN were on a self-actualization journey. Bells Hells have to do both of these things at once.
They're quick to trust, which opens them up for numerous betrayals. They don't have enough power to protect against the losses of friends or family. All they've got going for them is their collective aura of tragic weirdness and their full-on willingness to kill immortals (fucking delilah).
In a way, BH view themselves as monstrous abominations. They gain trust from the unlikeliest people and will try to befriend you if they think you're a fascinating monster like them. They've never agreed on anything ever, but they're open to a lot of impossible things and take it in stride. After all, their own existence is an impossibility. And I think that's fucking special.
