thanks for your comment. There are several important differences between the Immortal, and the Avenger. The number of paddles: The Immortal has twice as many paddles as the Avenger (The Immortal has 8 paddles). This allows you to configure your controller just the way you want, and to never take your thumbs off the joysticks. Improved Ergonomics: The paddles in the Immortal are located so you can use them with natural movements, reducing the fatigue in long sessions of gaming. And, since the ergonomics are a key factor, the size of the Immortal is optimized to favor it.
The Immortal is printed already assembled, so no complicated puzzle to build, and it comes in several colors. And for the price, the Immortal has the same price per paddle as the avenger.
I Hope this clarified things.