Armature Lag

Hello everyone. Here is a sample of what I’m talking about :

The main problem appeared to be the lag when animating. So I’ve cleaned up this whole file to find out why it is so laggy.
Although I’ve kinda deleted everything, but the file size is 1GB, that is the first strange thing. The models inside it shouldn’t weight so much.
And when animating it lags like hell even with simplify on. I’ve even tried to delete all the objects, but even the empty armature lag. I have no idea where is the problem, but I really wanna find out.

Don’t judge me too much, this file might be full of mistakes, thank you.