Well, aside from Jack, there could be his sweetheart, perhaps a local girl from the town where he was stationed. Her name could be Lily. And then there might be an older, wiser character like an old man named Mr. Brown who gives Jack advice about love and war. Another possible character is a military commander, Colonel Smith, who might have an impact on Jack's situation, whether it's related to his military duties or his love life.
Jack is likely the main male character in the story. He's probably a soldier or someone directly involved in World War II, and the love story revolves around him.
One main theme could be sacrifice. In World War Two, many had to sacrifice a great deal, and in a love story set during that time, the characters might sacrifice their personal desires for the sake of love or the greater good. Another theme could be separation. The war often tore loved ones apart, and the story may explore how Jack and his love interest deal with being separated. Also, the theme of hope might be present. Despite the chaos and destruction of the war, their love could be a source of hope for the characters.
Since it's called 'As Always, Jack: A Wartime Love Story', Jack is for sure a main character. The other main character is most likely the person he is in love with. It could be someone he knew before the war, perhaps a childhood sweetheart, or it could be someone he meets during the war, like a nurse taking care of the wounded soldiers. There's also a possibility that it's a fellow soldier with whom he forms a deep emotional bond that goes beyond friendship in the trying times of war.
Well, in the Eyeless Jack anime story, aside from Eyeless Jack, there could be a group of friends. Maybe they are out late one night and become the targets of Eyeless Jack. One of them might be a bit more brave or curious, and they try to fight back or understand what is happening. There could also be an old hermit - like character who has heard rumors about Eyeless Jack for years and has some knowledge about how to deal with such supernatural threats. And of course, there are the families of the victims. They are important as they are the ones who are directly affected by Eyeless Jack's actions and they might push for investigations or try to find ways to protect themselves and others from this horror.
One main theme could be the power of love in the face of war. Despite the chaos and destruction of World War II, Jack's love story shows that love can endure. Another might be sacrifice, as the characters may have to give up things for each other or for the greater good during the war.
In this fanfiction, Marshmallow could be a significant character. He's a large and somewhat intimidating snow creature created by Elsa. But with the baby on the way, he could become a gentle protector. He could stand guard outside their home to keep any potential threats away. Also, the trolls from the Frozen universe could play a role. They are wise and could offer their knowledge on how to take care of a baby with magical powers. They might even perform a special ceremony for the unborn baby.
There are the giants. They are the antagonists in the story. Each giant has its own characteristics, like being big and strong but also a bit dumb at times which Jack uses to his advantage.
His friends from the dojo like Milton, Jerry, and Kim could be main characters. They would be the ones to support Jack after the accident and might be involved in any investigations or helping with his recovery.
Since it's a Jack Ryan story, Jack Ryan is likely to be one of the main characters. But without more information, it's hard to say who else might be involved. There could be some new characters created specifically for this 'Black Jack' story, or it could also feature some recurring characters from the Jack Ryan series.
Since I'm not very familiar with this specific 'laughing jack love story', it's hard to say exactly. But surely Laughing Jack would be one of the main characters. There might be another character who is his love interest, perhaps someone with a very different personality to contrast with Laughing Jack.