I fully disagree. I'd say his intention was to make the people forget all about the Superd when someone else turned their city in a giant, dirty pool of water. Of course a bunch of people would most likely die due to flooding, but getting hammered by rain, no matter how heavy, will not automatically kill anyone. Even a Japanese person will just get a fever lasting for one or two days.
Edit: Somehow I got the timing of the events mixed in my head. Ruijerd hadn't even revealed himself yet.