That second ability is pretty powerful for 3 cmc.

That second ability is pretty powerful for 5 cmc.

Dunno, I'd have placed this around 4, personally. At four it might get the opponent to discard a couple of things; at 5+ your opponent will likely have emptied their hand (or been able to anyway). They might not have wanted to but hey, how is forcing a discard really much worse than just countering it?

I imagine that in the decks that play this, it effectively reads "Each opponent's maximum hand size is 0." That's got to be at least 6 mana.

­Jin-Gitaxias, Core Augur basically says that, and he's pretty costly.
Edit: Though of course his draw ability is very powerful.

Yeah, I was thinking of Jin-Gitaxias. Refilling your hand is probably his best ability, but surprising your opponent by making them discard their hand by flashing him in during their end step is pretty good too.

­Jin-Gitaxias, Core Augur was the only reference on my mind when I thought of this card. I saw Jin's draw as his best ability, but I know how powerful the second ability is. 3 definitely was way too low. I feel like at 7 this card would never be used anywhere.

I also only named it Dumb Down because I couldn't think of anything better.

What if it reduced each opponent's handsize by 1 for each card over seven in your hand? That's what I initially thought it did, and that way the two abilities actually scale together and it can be costed a bit more aggressively.

I actually really like that idea.

This is much more reasonable. I like it. Unlike the other, once you break this you've probably already guaranteed a win anyway.