Consider Dark Heart of the Wood or Savage Twister in Ravnica Block—powerful gold spells of old brought to a new multicolored home. Elves of Deep Shadow (welcome to the Golgari!) and Goblin Spelunkers (now with Sacred Foundry-walk!) also gain new talents in Ravnica, showing off the new value of their color-specific focus.
Cards like Lay Waste, Disciple of Grace, and Swat rode the “cycling renaissance” from Urza’s Saga to Onslaught, and Frozen Solid boarded a rather drafty flavor train from its origins in Scourge to the icy wastes of Coldsnap.
Back in Odyssey, the “gravedigger cycle” of Scrivener, Archivist and Cartographer joined the newly-minted Auramancer to highlight the graveyard-matters theme of that block. Reprints like Patchwork Gnomes and cheap cantrips like Guided Strike also drove home that graveyard theme. It’s all a matter of context.
So the next time you see a reprinted card, think about the context of the set it’s in; it may be an old card, but it’s sure to have new significance.