We don't talk enough about how cunning Aki and Haru were in the s2 finale against Yumoto.
They basically break him physically in the start. Easily overpowering him by their pure (petty) hatred
Then when they're interrupted, the twins know they have to change strategies with more physical force to try to keep Gora for themselves. Haru basically mocks Yumoto here, to in a way, distract him from his end goal of saving Gora.
By wearing Yumoto down, physically and mentally, Aki and Haru decide to unleash the thing they know would fully break him, which is losing Gora.
They do this sort of unintentionally, and end up panicking as they realize how they shouldn't have fucked with this kid. Even Atsushi notes on how sensitive Yumoto's own emotions are and how Yumoto's would overpower the twins'
I can't give the twins all of that credit but, I think they had a decent plan thought up when they would be fighting the Battle Lovers. They just didn't know what powers Yumoto's own emotions actually held.
But, I can at least say, this finale could have been a lot darker
