After becoming the sole survivor of his adventuring party a barbarian now protects the town’s children by slaying the monsters under their beds. But when a rise in monster attacks threatens everyone, he must overcome his survivor’s guilt and PTSD to save the town.

Most of the kids have parents. However, two of them would become orphans early on because the monsters kill their parents. Just so those two end up helping the Barbarian.

Also, I intend to write it primarily as a novel. Maybe adapt it into a screenplay or limited series at some later stage.

Sounds like an interesting concept. Good stuff

Perhaps the two sentences could be shortened and still accomplish the goal. For example:

After becoming the sole survivor of his adventuring party, a barbarian with PTSD must save the town's orphans by slaying the monsters under their beds.

I assumed the children were orphans. I hope to see the final script!

The idea is that the PTSD comes from seeing his friends in the adventuring party die, so it is the same reason he has survivor's guilt. I guess it's not as apparent as I thought it was. Thank you for your input.