Clint: Killing people-- especially killing people who aren't strangers (when he operates as a non-war sniper). The latter has been quietly wearing him thin for years, though. Killing dangerous strangers doesn't really bother him?? Especially aliens and robots they are kiiind of fun.

Chuck: People he knows dying violently or seemingly mundanely through the build up of concussion on concussion or radiation poisoning or falling from great heights. As a Jaeger pilot that's just life. It's only in Milliways that he's really started to unfold and consider lives where that is non-standard (which he thinks is great, but still in no way internalized that his was at all weird or pitiable. Pity would make him really uncomfortable!).

Melinda May: Leaving people she loves in danger. It's both a necessary part of the job and slowly (painfully) removing their wellbeing from her personal responsibility is the only way she avoids another major breakdown.

Legolas doesn't think any of his life is traumatic but I'd say watching his home being slowly twisted to evil. Since he sees it as an active thing to fight he wouldn't say he is used to it (or traumatized by it) but it was something that definitely upset him much more when it started and is now his new normal.

Sebastian has not normalized any of his trauma. He particularly hates the sea and infections.

Quatre has no concept of personal trauma, which is bs because he's endured so much. Having decisions that effect the lives of millions in his hands; monitoring himself for psychosis fiercely; feeling people die with his empathy.

John Connor thinks it is normal to be on the run for your life from cops and evil robots. No place is ever safe, amirite.