Athenium

From BoardGameGeek:

Athenium is a head to head summoner battle game in line with most popular trading card games. What sets Athenium apart is that it is permanently simplified to the most basic elements of gameplay. Starting life points are determined by the number of players. Each player involved adds 5 life points to the starting life point total of every player. It's meant for 2 players, starting at ten, but it's still really fun with 4 players, starting at 20. There are still resource cards, called Macguffins, that are used to motivate a character into the battle, but instead of 4-7 colors, there are 3, and they are based on genre. The green cards are Fantasy characters, the blue cards are Science Fiction characters, and the red cards are Horror characters. Each character card has one number, which represents attack, defense, and casting cost, which go up or down based on their type matchups. They attack and block left to right, just like reading a book. When the defending characters run out, the rest is damage dealt to the defending player. When the defending player runs out of life points, they lose. Last librarian standing wins. Everyone plays from one deck which may be supplemented with special cards, or later expansion decks. All of the art, graphic design, writing, gameplay architecture and web design were done by Ben Butcher, though the expansions have other illustrators on payroll in the near future. -description from the publisher