I'm thinking of moving his toys to the basement
Why do you want to move his toys?
He never cleans them up, I am so tired of seeing them all around. I will put them away for good.
It can be frustrating to have too many toys in one place but you cannot move them without getting his permission. They belong to him and he should decide where they should go otherwise he will be upset.
It's not like he's going to cry about it and he would easily forget about them. This boy will forget about the toys by tomorrow.
I hope you can teach him some responsibility. He should be able to pick them up himself before he can do anything else like videogames.