I think I'd not even be mad if this was - it's such a straightforward "mostly better in multiplayer only, but still not really since it doesn't even scale with player number" effect compared to Mind Rot.

What's the most extreme thing this adds to 1v1? Having an opponent discard oe, but also discard a card yourself fo r some combo?

I think a modal "Target opponent discards two; or each opponent discards one." would be more appreciated.

I dunno; the wording is flexible enough. Sure; it's basically a functional Mind Rot reprint, but the tiny extra bit of flexibility for multiplayer or playing madness, seems useful.