On that note, it is probably the case that this specific setup that is allowing bam to overwhelm white (black shinsoo rain plus endless stream of bangs) wouldn't work on kallavan. Since kallavan is so absurdly durable he would be able to simply take the rain as if it was nothing. Hence kallavan wouldn't waste any of his capacity to control shinsoo defending from it like white had to do.
I don't actually agree. Yes, Kallavan's defense is top notch, but White was able to damage him. White only got to Baam because Baam let him... his shinsoo was overwhelming White and he wasn't able to break through it. I don't think kallavan would be able to just sit there and wait all day waiting it for end.
What Baam is doing now is different from what he did with kallavan. Against Kallavan he was trowing endeless shinsoo from the loops. Now he's taking control of the area a la hell joe. White is protected because of his barrier density.
He's also fueling the loops with the shinsoo from the area he took control. Is too much shinsoo in a small area, making it rain. The rain isn't an attack, it's a side effect. A simple side effect that's constantly damaging White's barrier.
On top of that he's using the meteor shower.
At least that's what I'm getting from his shit.