The discovery of a black crystalline mineral known as Originium has accelerated technological advancement in the world of Terra, with its high energy yield allowing people to demonstrate abilities akin to magic called Arts. Large veins of Originium can naturally be found at the sites of Catastrophes, various forms of natural disasters caused by the mineral itself. However, the usage of Originium comes at a price, as there is a high risk of getting infected with Oripathy—an incurable and highly contagious disease. Because nations subject the infected to harsh discrimination, the oppressed begin a dissident movement. Calling themselves Reunion, the rebel faction mercilessly destroys cities, further contributing to the already calamitous nature of Catastrophes. Rhodes Island, committed to treating the infected and uninfected as equals, is a paramilitary pharmaceutical organization believed to be the most advanced in its research for the Oripathy cure. Unfortunately, the person spearheading the project—an enigmatic figure known only as the Doctor—suffers from amnesia, effectively impeding what might be the only hope for the infected to break free from their chains of despair.

Second season of Arknights.

For the past 13 years, the Nefarious Monster Army have appeared beneath their floating fortress every Sunday to advance their goal of conquering Earth. Luckily, the Dragon Keepers are here to save the day! Having defeated the majority of the monsters during their initial invasion, the heroes now routinely show up to clear away any remnants of resistance. Unbeknownst to the public, however, every fight beyond the first has been a deliberate show put on by both sides: the Dragon Keepers reap the fame and prestige from fighting imaginary enemies, while the surviving weakest monsters, altogether called Dusters, are allowed to live for another day. Sentouin D, a Duster tired of living this life of shame, leaves the fortress in an attempt to overturn his fate. With the unexpected help of the mysterious ranger Yumeko Suzukiri, he discovers the key to defeating the Dragon Keepers lies in their Divine Artifacts—ultimate weapons crucial to the rangers' transformation and unique powers. Teaming up with Suzukiri to infiltrate the garrison of Red Keeper Sousei Akabane, Sentouin D must defy all expectations to save his species from the cruel hands of humans.

An animated short for the Arknights smartphone game's 1-year anniversary. (Source: ANN)