is chainsaw man episode 12 filler?

Akane sends the "Ghost Devil" after Aki, and he's nearly killed before the "Ghost Devil" stops and hands him a cigarette with a message from Himeno. The words inside give Aki the strength to kill the "Ghost Devil" and capture Akane.

Meanwhile, Denji heads into his rematch with Samurai Sword. With a pull of the starter on his chest, he transforms into Chainsaw Man.

And now, the last battle between Chainsaw Man and Samurai Sword has finally begun...