Now that we get the secret regarding RUM's identity out of the way, it is reasonable to presume that this will be one last "daily case" arc before we reach the final arc and the ultimate confrontation. Before that, a few subplots need to be cleared, and a preparation for Conan Team for the confrontation.

Remaining subplots

• Heiji and Kazuha's Relationship Upgrade

This is one of the most important thing that needs to be done before the final arc. By this point, it's unlikely for Heiji to be able to confess easily, so it's reasonable that certain "life and death" situation must be given like another serial cases, though I also wish that it's Kazuha who gets to confess first. Momiji is going to play some prominent role too.

• Kogoro and Eri's Relationship Status

So far, we know that they still have feeling for/need each other but don't want to admit it. They could stay living apart this way since it has already been many years and Ran can more or less accept this even though she still wants them back together. However, if there is going to be a reconciliation development then similar to Heiji and Kazuha there is going to be some serious situation first.

• Akai Family and Tsutomu

We still don't have the full picture regarding Tsutomo's whereabout, and Mary and Conan have yet to form any contact with each others.

• Rumi and Kuroda's identities

Self-explanatory. We still need to figure out their identities.

• APTX-4689 and Silver Bullet

For the antidote subplot, and is also connected to Akai Family's

• The Software that Vermouth ordered Itagura to work with

Which has yet to be revealed

• Koji Haneda, Amanda, and Asaka

Gathering Allies

• So far, Conan still have a very limited allies in confronting the BO: Yusaku, Yukiko, Agasa, Ai, Heiji, the FBI (Jodie/Shuichi/Camel/James), Hidemi, Eisuke, and Rei. Of the stated people, onlyYusaku, Yukiko, Agasa, Ai, Heiji, and Eisuke know about his true identity. EDIT: Shuichi, Masumi, and Mary are suspicious of him being Shinichi, but have no hard proof/confirmation from Conan himself yet.

• Aoyama once said that Kaito won't be participating in the final battle, so no him.

• The Akai Family will prove to be an important allies due to Mary's connection with Elena, providing that Conan is able to convinve them to join him, instead of fighting the BO on their own as Mary planned to once she obtains an antidote.

• At this point, it remains if Ran and Kogoro will be joining the team, since Conan getting exposed as the brain behind Sleeping Kogoro is pretty much a tickling timebomb with Wakita snooping around.

• If Heiji is participating in the final battle, it may also be necessary for Kazuha to know the situation.

• Makoto is a very powerful ally as he is literally "cheat mode". However, he is very much outlier in the story, and is unlikely to join the battle unless Sonoko is involved.

• Conan and Ai are unlikely to reveal their secret to Ayumi/Genta/Mitsuhiko, as their greatest fear is getting the kids harmed/killed. However, given how the FBI Serial Murders started, they may be involved with the dangerous situation again.

• Tokyo Police Department is the least likely ally, since the FBI don't want them to get involved. But as they're continuing to be cornered by the BO, more power force is necessary. This one might easily be managed if Kogoro and/or Kuroda is their ally.

The Enemy

• The Boss, whose identity is assumed to be Renya Karasuma, is an intelligent and careful individual. However, he still remains in mystery and will probably be until the final arc.

• RUM is the second in command, whose personality is crafty and intelligent like the boss, to the point that he carry out spying on the enemies and weeding out the spies himself. A formidable foe, but Conan may need to use him to trace back to the boss.

• Gin/Vodka/Chianti/Korn so far have no backstory associated with the plot, so unless there is a new development then they will just be the main obstacles between Conan Team and the boss.

• Vermouth is the Wild Card of the BO. If we take her words as truth, then there is a good chance that she will be helping Conan Team toward the final.

Almost Out of Time

• It can be presumed that Wakita/Rum is trying to figure out the truth behind Sleeping Kogoro and weeds out all the spies within the Organization (which should be easy if we assume that the non-trustworthy members are grouped under certain types of alcohol like this post). So the deadline for Conan is that Sleeping Kogoro is exposed, or the spies within BO:Hidemi and Rei; are in deep trouble.

Win Condition

Conan has certain goals to fulfill in order to win this biggest war of his life.

• Survival: Depend if Gosho is willing to kill any of the main and recurring characters introduced so far, Conan's main priority is to make sure that his friends and family survive this battle. This of course, may depend on him revealing his secret to certain characters.

• APTX-4869/Silver Bullet Recovery: Returning back to being Shinichi is his personal goal that he wants to fulfill. Contact with Mary and getting to the boss will probably have this one done along the way. This goal also might be closely related to Vermouth's secret.

• Bring down the BO and its boss: The ultimate goal of Detective Conan itself, and also the hardest goal to fulfill. Not only they're going to track down the boss, but they also have to fight against all the executives and assailants under BO's control.

• Solving all the Mysteries: This is more of the readers/fans' goal: all the accumulated mysteries so far will have to be solved before the main story reaches the end of the road.

Overall, I do expect the last arc to be quite action heavy and plot heavy, and somebody (mostly on the villain side) might not survive until the end.