They both horrible people, and it’s almost never a good sign for William & co if they show up.
They are a bit similar. They both want to kill William. They both abusive to Sytry and Uriel, and yet Sytry and Uriel respect them.
Both look down on former humans, yet they made Gilles and Metatron a demon or an angel.
Though I think Baalberith is currently better, if only because he appeared recently. It’s been a good while since Michael has appeared. And he is currently fading due to lack of sleep, and he doesn’t seem to hold much sway over the other angels. While Baalberith is not dying, and has enough sway to send the freaking army after Dantalion. On a lie,