No, he expected those wires to destroy the sword. That's how crazy those wires are.
And in fact, 666 didn't manage to cut those wires. She could only buy some time to get out of the current.
I think this is also a wake-up call for the girls
They've been careless since Sanzo made the promise (e.g., leave him alone in the Taoist country)
Even if he's indestructible & honors his promise, stuff like this can still happen
I can't believe the teacher took that long to realize what happened.
If I were to teach a class with Ruri in it, I would be worried 247
Especially when she is surrounded by kids with all of the curiosity & none of the self-preservation