Courtesy of Wizards of the Coast (WotC) and Eric Froehlich, check out the spiritual successor to Sulfuric Vortex in Zendikar Rising — Roiling Vortex!
This two-mana enchantment can do a little bit of everything that red mages could ask for. Dealing a point of damage during each player’s upkeep not only provides decent pressure by itself, but also enables plenty of powerful spectacle cards, such as Light Up the Stage and Skewer the Critics.
Whenever a player casts a spell, if no mana was spent to cast that spell, Roiling Vortex deals 5 damage to that player.
Time to tax those free spells! While this ability may impact games less frequently than the others, when relevant, it shows up in a big way —punishing cards like Dreadhorde Arcanist, Bring to Light, Bloodbraid Elf, and many more.
R: Your opponents can’t gain life this turn.
This is likely the biggest draw to this card; a cheap, consistent way for red decks to shut off their opponent’s life gain. While similar sideboard options such as Rampaging Ferocidon or Tibalt, Rakish Investigator have existed, the additional abilities, consistent damage, and generally being harder to remove will likely lead to Roiling Vortex getting the nod in future sideboards.