Rick Remender 
Low Vol. 4: Outer Aspects Of Inner Attitudes [PDF ebook] 

Tajo returns to her family home on Salus, to find a city on the brink of devastation. There is no food, no air, no hope for mankind’s last great dome city. Now, Tajo must band together with IO, a man carrying a secret millennia old, and Mertali, a brave mermaid from the gladiator pits of Poluma, to fight for a better future for everyone. But death stalks the desolate streets of Salus, a ruthless killer who will stop at nothing to see the city drown in its own blood?a killer that Tajo created, and now must face again one final time. Collects LOW #16-19