The card got reprinted in MTG Foundations, and now occasionally appears in Standard aggressive decks, as well
Seven mana is a bit much to ask if youre not winning the game the turn you attack with it, but for the cost of Unburial Rites, its a much more exciting card
Some, like [c]Viscera Seer[/c], can be activated at any time
Hangarback Walker is high on my list of cards to support sacrifice decks and delirium, and while it has the potential to be significantly more powerful than Solemn Simulacrum I believe it firmly lands in the category of colorless cards that feel like youre paying for what you get
Even the primary commander from The Ruinous Powers, Abaddon the Despoiler, grants cards in your hand cascade if their mana cost is equal to or less than the amount of damage dealt to your opponents in a turn