I think the ending will be really surprising. Like Conan will get surprise when he'll meet the boss of the BO. Also, if it regards to Shinichi and Ran, I think the story will be like this....
After Conan defeat the Leader, the place will earthquake (i'm sure it's common, in some animes). Everyone's outside the building waiting for Conan. especially Ran(let's just say she already knew about the black organization, but still didn't know about Conan's true identity). Then Conan fastly find the way out but he can't leave the boss die( i don't have a clue on who will be the boss). Then he should solve a puzzle to get out. The boss will asked why is he saving him? then conan will answer a very thoughtful one while solving a code. Then the torch fall and it caused the place to burn. Conan who's thinking really hard while the boss is in panic. the fire is near on where they were. until, Conan solved the code and they safely goes outside where's everyone. they were greeted by everyone but then Conan fainted because of lack of oxygen because of the smok. the moment Conan wake up, ran and Ayumi are crying. Genta and Mitsuhiko are sad Of course, Ai too. Conan said softly," Don't worry i'll survive, I promise!" Then Conan said towards Ran," ran-neechan, if I will survive I wanted to tell you something." Ran said," i'll wait for you to tell me, conan-kun." Conan smiled and closed his eyes. After a few days, dr. agasa visited Conan onthe hospital. Conan whispered something about him. Dr. agasa just agreed in it. His parents also visited him and of course, Conan tell them something similar on what he said to Dr. Agasa. He also told it to Ai. His father also tell it to some of the nurse and doctors. They also agreed. After a few days, Ran visited again. ran asked about what Conan told her in the ambulance. Conan blushed and thought," It's time." Conan said," A-actually...Ran... I'm..." then suddenly Conan wasn't feeling well. Ran got worried and kept repeating his name. Conan continued," Ran...Before I say goodbye..." Ran demand," No, don't talk it'll be bad for you and don't tell me you're leaving me too." Conan continued," Goodbye Ran, before I leave I wanted to tell you for a long time the truth that I'm actually...Kudo Shinichi..." Ran got surprised," What are you saying? Stop joking around, Conan-kun" Conan said," I'm not kidding It's true. I'm Kudo Shinichi and I wanted to tell you for a long time that..." Conan's in the emergency room actually and saying his final words to Ran. Conan's voice become softer and softer," I... Love... You.... Ran..." then he closed his eyes. Ran cried and said," No!" Then after many days, Ai visited Conan's grave. Ai put flowers and said holding a drug," Hey, Conan-kun just like i promised Here's the antidote from the drug I made." Ai wasn't so sad. Then someone was hiding behind the bushes. Ai said," You don't need to hide and pretend anymore kudo-kun" A boy came out." you got me there! Ai" The boy said. Ai toss the drug to the boy. Ai said," You're plan is successful I guess. Pretending to be dead in front of Ran and then Hiding at Dr. Agasa's place for a long time and disguising himself, Then stalking at Ran..." Conan said," hehehe, glad i include you to the plan." Ai said," hurry Up! Kudo-kun. You're princess is waiting for you." Conan said," thank You for everything, ai." Ai said," no Problem" Conan left and goes to Dr. Agasa's place. Conan told what ai said to him to Dr.agasa. gasa agreed and said," Tell me what happened, okay" Conan agreed. Then Conan drink the drug and he became Shinichi again. His parents also came back and hugged Shinichi. Yukiko said," Now, For the final" Shinichi nod. They goes to ran's place. Sonoko's there knocking at the door of Ran's room. sonoko said," ran... what's wrong! Please come out for a liitle while" Ran didn't reply. Shinichi said softly," hello, Sonoko!" Sonoko got surprised,"k-Ku-" Shinich covered her mouth.ran heard what Sonoko said. ran said while crying," Sonoko, Is Shinichi there?" She fastly open the door and saw Shinichi's parents. yuusaku said," hey Ran we've got a present for you..." ran demand," i don't need presents" yukiko said," don't be harsh, Are ou ready?" Ran said," ready for what?" yuusaku said," To se our present..." ran said removing her tears," fine! ready!"Shinichi's parents move backward then sideward and Revealed a young man standing. Ran got surpised and fastly Hug the man. She said," Shinichi!!!" as she cried again. shinichi said," hey! don't be so dramatic." Ran said," idiot! idiot! idiot! I thought you'll leave me" Shinichi said," don't worry I'll never ever leave you again I promise..." Then everyone left. Shinichi confessed to Ran everything including He loves her.
That's all I think. Shinran together always....
