The cards in MTG core sets were typically reprints of some of the most popular cards from previous releases
It's a nice and slightly creepy way to represent the ancestral spirits watching over the living tribe
Fortunately, if you are looking to pick up some Decree of Silence for cheap, you can get worse-conditioned copies for a bit less
Cards like Phytotitan, Malignus, and Daemogoth Titan are all great targets to be sacrificed to Ziatora in order to deal some real damage, The treasures generated by Ziatora also enable you to work some artifact synergies into your deck, or even pull off a Revel in Riches win
As such, making sure the cards worked in Standard was going to be a monumental task
It provides the ability to grind out when you run out of cards, almost giving you an extra card draw each turn, but better, as it's a permanent of your choice from your graveyard, nulling any efforts by your opponent when using removal spells