Did you try turning off your flames, did it still lag?
What's the regular fps you have while playing and what's the fps you get in the "menu" part of the Torishop and the items' preview part of it?
I turned off my flames, and my regular FPS is 60 when playing, and I got about 10 in the shop
My signature was too long so I got this pretty rainbow here instead now. Isn't it nice? This is a nice rainbow.