I don't own One Punch Man, Ben 10, or any of the characters or media put here.
===============================
The next day came and Saitama was at home watching T.V.
BOOOOM!!
...Until he heard that noise.
He groaned, got off his chair and looked out the window. And when he did, he saw this giant from afar.
Saitama narrowed his eyes, made the wristband appear on his right wrist and said,
Saitama:Hero Time.
Then he teleported.
================================
Back with the giant, he was sitll walking on top of the city, deatroying buildings and killing citizens.
Then with a swipe of his hand...
BOOOOOM!!
...he destroyed a city block.
This mad scientist hanging on the right side of his shoulder saw the whole thing.