Marvel/DC: Dark Legacy

A boy saved a girl who happened to be the future soul mate of an Eldritch God named Sepul: The Black rabbit that Devoured the Sun, and obviously more than thankful proposes a deal a random world with his abilities which are all darkness, and shadow based abilities, but as an extra thanks this God decides to give four extra abilities to start with only catch? not really a catch but only one can be op, and has to have a activation condition oh i didn't mention this, but he must train. Now though let's see the adventures of August with his Character Synergy system.