If you're looking for manga similar to Code-Ex, you might like these titles.
This life: whose decision was it? Those who stride across the land. Those who dance across the skies. Those who are ensconced in water. What "entity" has been designed as the best form of life? The disturbing situation unfolding deep in the forest will shock the natural world and humanity!
Gen, a recently bankrupted and now homeless guy, meets an unusual hungry girl named Hios who can eat anything with her chopsticks.
In the future, humanity has been all but destroyed, only a small portion remains alive. A group of winged girls called angels must fight against the flying marine monsters attacking from the oceans.
Includes the following chapters:
Takagi Shuhei meet a man through a strange window. This man introduce himself as Takagi Shuhei' future form.
Ekijin (God of Pestilence) Syndrome is a disease that manifests paranormal abilities in an individual that eventually leads to death. The cause is completely unknown, and the only remedy is symptomatic therapy. Your family, friends, or even you can be suddenly infected and become the grim reaper itself. However, there are people who resist and fight against that hopeless disease. They are the Treatment Execution Organization's specialty division, "Ekijin Corps." Though those within the unit are infected by the disease themselves, they wield their paranormal abilities as weapons and wager their lives to rescue the infected. In order to protect the lives in front of them and to win against the disease that will undoubtedly take them in the future, the doctors will fight until the end.