That sounds like an awesome dream! ε=ε=(ノ≧∇≦)ノ If its something you enjoy doing you should use the context of your dream for a story as that would make an awesome story!(๑•ㅂ•)و✧
But if writing is not your thing that's still a great dream, I have never dreamed about characters I read on a webtoon so I am a little envious.(⌒▽⌒)
That's a great idea actually!! I shall try it next time!!
I have my most vivid dreams during the day while I'm having a nap cuz I stayed up all night. Idk if it would help but try sleeping in the afternoon after reading something , it might work (?) . Again I'm no sleep scientist ( as much as I would like to be ).

Guys I had the weirdest dream and it might sound kinda creepy but like I met truck-kun and was isekaied into the world as like a kid who Paulina took pity on and thought how to use a sword and stuff, and I was just living a happy life with this amazing woman right here. Sadly i can't remember the details now cuz it's all blury but I do remember her telling me something along the lines of - "Go forth my child for I cannot join you to help you face the hardships of your world, as much as I would like to" and then i woke up feeling like I was on top of the world .
P.s Ik it sounds Hella cringy but I had my English exam the following day and I guess this is what happens when you sit and try to cram Shakespeare.