You shouldn't have asked about Dubai (Spoiler)
Spoiler I guess, but it's not a major character, only on screen for a few minutes.
I hate, hate, hate, hate, hate, hate, hate this trope. The killer soooo badass and secret he kills anyone who even smells of knowing who he is. That is so demonstrably stupid. He's a killer for hire. He, clearly, works with and for others. He employs people to make things, fix things, provide material support.
Who would ever, ever have a business relationship with someone like that. If I was sick, sent over my trusted lackey and you killed him, then at the least I guess I don't ever work with you again. Word will probably get out.
Oh, you are super awesome and that's why people hire you anyway? Not if you need others to do some technical tasks. And then they won't work with you. Now you are not effective, so no one hires you.
Get some people skills and business sense. Please. Ugh.
Rant off.