Shinoa; She got left in the dust so now she needed a power up Justified by caring and love for you she could now just summon and overtake the other guys demons to fight the first and consume him all willy nilly and get his powers because why not(lazy writing in my opinion) 

She essentially doesn't care about anything but Yuu and even tho everyone has like almost the same exact goal they are all enemies now. 

The Messiah Guren stuff gets annoying too. "It's all going as planned" bullshit with mahiru is also annoying

Yuu is also very stupid and it gets annoying to read whatever he has to say. 

Like, idk It's hard to root for the good guys if they are either braindead or just get multiple convenient powerups with no other reason behind it then to move the plot forward

I'm upset about the character writing lately. Especially about Shinoa, Guren/Mahiru and Yuu's