Void Wall

[Vicotnic]

Void Wall
B/UB/UB/U
Creature -- Wall
0/3
Defender
If a creature would deal combat damage to Void Wall, instead that creature's controller puts that many cards from the top of his or her library into his or her graveyard.
(The cost is supposed to be 3  hybrid mana.)

Well, this card was part of my ideas for creating a none-combo standard viable mill deck. Pretty much a Wall of Shadow version with built in mill that should help holding aggro at bay while contributing to the milling.

[Matt]

Could easily be 0/4 for that price.

[Vicotnic]

Maybe but it is quite hard to deal with for aggressive creature decks already since it is black which makes it immune to a lot of spot removal. To also have toughness 4 would make it immune to most bolts as well. Maybe not overpowered for 3 hyrbid mana but very good and I don't think it is needed. A better card is not necessary a better design, and in the right block I think it would see constructed play with toughness 3 (compare with wall of shadow that is a 0/1 for  without any advantages save immunity to combat damage worth mentioning, not the best of cards and quite old but still.).

[Matt]

Oh wait I didn't see that it was a replacement ability. The toughness almost doesn't matter in that case.

I think a 0/4 Wall of Souls that milled (on any damage) would be more interesting (and could cost less).