In the second scenario, after you put the joint plugs in, you will fight a evolved form of Tyrant. Use the following steps to easily defeat him. For Leon, run to the right from him as soon as the scene (with black lines at bottom and top) ends. Start shooting him with the custom magnum three times, then run toward the exit door. Ada Wong will appear and drop a special grenade launcher. Run towards the grenade launcher, pick it up and shoot one shot to kill the Tyrant. If you are not an expert, you will also need first aid sprays or herbs. For Claire, you will do the same thing only using the regular grenade launcher with acid rounds. After this Tyrant, you will open the gate and get on the train. Another intermission sequence will play. After it finishes, the train will stop. Run towards the back of the train until you see a tentacle drop down. Another intermission sequence will play, and you have to fight the last form of William Burkin, as a revolting blob. Run towards the front of the train until you reach the door. Stop and shoot him with the remaining rocket. Then, use the custom magnum or a grenade launcher with acid rounds. Shoot him until he melts. After that, go to where you started and watch the ending sequence.