Technically there were cards with cumulative upkeep in Modern because of Coldsnap , but most of the good ones are looking for the number of age counters for some beneficial effect, making the interaction less valuable
As the ability resolves, the battle's controller exiles it then casts the back face from exile without paying its mana cost
For example, if you control Elsha of the Infinite ("You may cast noncreature spells from the top of your library") and Keeper of the Crown is on top of your library, you can cast Coronation of the Wilds, but not Keeper of the Crown
Gold Stars were a 2004 to 2007 thing, illustrated by Masakazu Fukuda, with a gold star next to the name and a shiny alternate-color print
Mirri, Weatherlight Duelist Another popular (but cheaper, mana-wise) Commander is Mirri, Weatherlight Duelist
Sensei's Divining Top, Mystic Forge, and any cost reducers that make Top cost like the Herald or Sculptor, let you draw your entire deck by continually putting Top on top of your library and recasting it with Forges ability