Umm yeah this is a thing.

So when I use brave burst,meaning: Im activating all of them at the same time,my game crashes. Its the graphics,its always the graphics,they cause lag,now when your monsters are low,meaning:unevoled,their BB is low in style or in this case graphics. Maybe strengthen the capacity of or in this case make it able to handle. But I do feel some monsters need more evolutions. Their weak,a lot of them are weak,I have to rely on gods now. Thank you. Its unpleasant to turn off the graphics.

Martha shards family about Brave Frontier, v1.4.81