It actually wasn't a comic. There's a series of novels that follow the main characters. It's cool how they do it because non of them actually follow any of the games. They all take place before or in between the games.

I've read the slab and it was a good ass book man I tell ya what

Yea that's the first of the series, Aspho fields is the second. If you liked it I highly recommend the rest of the series. The books that take place in between gears 2 and 3 are particularly good. It answers a lot of questions like where they went after they sunk the city, the initial discovery of the lambent, why Prescott was so hated and why they were so shocked when he showed up at the beginning of gears 3. It's what I love about the series. You have a much better understanding of what's going on in the games if you've read them.