Ajin, Inuyashiki Recommendations
Planes being used as weapons by unkillable sociopath villains that take bullets from armies of normal humans, then get back up and kill everyone shooting at them, no puks given. The same sort of entertaining craziness, in short.
In both Inuyashiki and Ajin, the main characters are immortal. In Ajin he will not die no matter how many times you kill him, and in Inuyashiki they are a machine. Both series also contain dark elements.