King in Limbo is a comic about trauma--in its protagonists (the manga opens with Adam in the hospital after getting blown up, and he's still in better condition than the King of Limbo) and in its plot (the whole plot is about a pandemic that makes trauma multiply till its victims expire from sheer agony). I didn't find it a hard read myself--this is an action thriller comic, not a horror comic--but it has some heavy themes!
OMNIBUS 1 (vol. 1-2): Hospitalization, major physical and mental injury (but not gory) resulting in disability, a pandemic, and untrustworthy government behavior. War crimes. Violence. Also allusions to an abusive Dad. Memory deletion.
OMNIBUS 2 (vol. 3-4): Violence, murder, more untrustworthy government behavior, emotional and physical child abuse, reality distortion, childhood bullying. Memory deletion.
OMNIBUS 3 (vol. 5-6): Violence, murder, emotional and physical child abuse, reality distortion, childhood bullying, comas. (This is a coma-heavy series.)
Content Warnings
OMNIBUS 1 (vol. 1-2): Hospitalization, major physical and mental injury (but not gory) resulting in disability, a pandemic, and untrustworthy government behavior. War crimes. Violence. Also allusions to an abusive Dad. Memory deletion.
OMNIBUS 2 (vol. 3-4): Violence, murder, more untrustworthy government behavior, emotional and physical child abuse, reality distortion, childhood bullying. Memory deletion.
OMNIBUS 3 (vol. 5-6): Violence, murder, emotional and physical child abuse, reality distortion, childhood bullying, comas. (This is a coma-heavy series.)