Responses
Im not 100%sure, since the novel translation i red was translated by google, but i think thats the solution. Dimitri hired Leonid to kill Leewon and Leewon now hired Leonid to kill Tsar. When Dimitri learns about it, he's going to protect Dimitri and goes against Leonid. It wasn't really resolved in the novel till the end, but your theory is correct. Either Leonid or Dimitri dies first, Leewon safe now.
I haz a theoryyyy
Okay soooo I think Leewon put a hit on Caesar to bait out Leonid and get Dimitriv to act. If Leonid going after both of them, Leonid would be around more. This gives Caesar and Leewon more of an opportunity to act against him. Because Leonid is going after Caesar, Dimitriv is going to go after Leonid/prevent Leonid from killing Caesar. If they get lucky, Leonid and Dimitriv gonna to kill/harm each other. Both would take each other out. Caesar was going to kill them anyway based on chapter 85. Leewon is planning on pitting them against each other.