Grimoire of the Dead
{4}
Legendary Artifact
{1}, {T}, Discard a card: Put a study counter on ~this~.
{T}, Remove three study counters from ~this~ and sacrifice it: Put all creature cards from all graveyards onto the battlefield under your control. They're black Zombies in addition to their other colors and types.
Liliana Vess
{3}{B}{B}
Legendary Planeswalker -- Liliana
5
[+1]: Target player discards a card.
[-2]: Search your library for a card, then shuffle and put that card on top.
[-8]: Put all creature cards from all graveyards onto the battlefield under your control.