Hi there and welcome. Well, I have a 9 year old boy and a 10 year old boy. In truth, they have vivid imaginations, play pretend, daydream about being super heroes, etc. My sons have light saber fights by themselves with no light sabers. You've heard of air guitar? They do air light saber, air guns, air bow and arrows, etc. They pretend they are flying and things like that.
Not every kid is like that but a lot are. I would imagine that your son has a protective cocoon around him. When you say he really believes there is a team of assassins around him at all times . . . okay. Probably he doesn't REALLY believe that. But it makes him feel good to say it. He's a boy that has had a bit of neglect from a crummy mom . . . BUT, that was his norm and he's been removed from it. While I'm glad you have him --- it's also quite hard on a kid to be uprooted from a familiar parent. His pretend world offers him comfort.
I would NOT worry about bringing him back to reality right now. He'll get it. As long as he isn't doing anything dangerous like REALLY jumping off the roof to fly . . . I'd let him be. Maybe once in a while, check in (son, you know you really wouldn't want to shoot a canon at the cat, right? It would hurt the cat and make a mess of the house.)
If you believe he really has some mental health issues, then I would definitely begin therapy with a psychologist.
But, you'd be surprised the things kids come up with and they are perfectly normal kids. I used to play house and would continue playing when with my parents without telling them I was still playing but in my head, the game went on. I'm a grown up now and cant believe I used to think playing house was fun (ha ha).
i agree with Specialmom completely. Another thing that you might want to do is to play a few video games with him. Pick some good ones. Of course, any outside activity together would be better.
To be honest with you, I am very concerned about any emotional issues your son may be experiencing as a direct result of parental separation, the friction he witnessed and perhaps continues to witness between you and his mom, and any kind of mistreatment he received from his mom that led to you gaining physical custody.
True - Kids tend to have and should be expected to have a vast and overactive imagination. However, when he is unable to determine fiction from nonfiction, he very well could be living in his imagination in an effort to emotionally cope with family stressors (coping mechanism).
If you feel that this behavior is negatively affecting your son socially, occupationally, and academically, it is time to get him evaluated by a mental health professional ASAP.
All kids have vivid imagination. Its as if they have a world of their own. Most likely it is also his way of coping to his situation. But if your father instinct tells you that there is really a cause for concern then you should bring him to a child psychologist so he can be properly evaluated.