After finding the secret entrance to the Wonder City temple, continue down the corridor and head up the ladder. Batman's condition is getting worse now and he collapses. A door will open, and you will see two figures in the shadow. Martha Wayne will tell you that you need to step into the light, your father and her are waiting for you. Oracle will contact you and wake you up. She will tell you you only have MINUTES to live. You tell her you will make it.
Keep going and enter the Chamber of the Demon. Some ninjas will appear. Talia will be amongst them. Ask her where Ra's is. She will say that only a true successor may stand before the great Ra's Al Ghul. Tell her you are there to stand by her side, become an assassin. She will ask you if you are prepared to take the demon trials. You must show that you are willing to take a life to save the world. Tell her you are ready. Let the trials commence.
She will lead you down a tunnel past some guards toward the location of the trials.
FIRST TRIAL
You find yourself in a small room, with a chalice in front of you. You hear Ra's Al Ghul voice:
"Welcome detective. I am the great Ras Al Ghul. Before you lies the first demon trial. Simply drink from the chalice. It is that simple."
Do as he says. Drink from the goblet. The blood of the Demon will restore batman's health for now.
Your next task is to follow him through the world. If you touch anything, you will die. Follow the trail of the ghost. The key in these next sections is to alternate between dive bomb and a steady climb to cover large distances quickly. Grapnel onto the large pillar when in range. Follow the same procedure to get to the next pillar. Whatever you do, do NOT touch the ground. If you do touch something and fail, you will go back to the last pillar you stood on.
In that second pillar you will be attacked by two ninjas. Defeat them. Keep following the trail, which will this time lead you down into a volcano. This begins Ra's 2nd trial.
SECOND TRIAL
You will land on the roof of some building. Follow the trail of the Ras Al Ghul's ghost again. This challenge is a bit trickier as the trail takes you through some structures, be very careful not to touch anything. Grapnel onto the next platform when you have cleared the structures. Ras will tell you that your body is becoming weaker, and that the small quantity of the blood of the demon you drank will only keep you alive for a few more hours and that now it is time for you to make the ultimate decision.
Follow the trail again. When you reach the top of the next pillar you will be attacked by 4 ninjas. After you defeat them, Ra's Al Ghul says:
"It is time to face me in person. Complete this final challenge and the blood of the demon will give you the gift of eternal life."
Follow another trail into the another volcano.
THIRD TRIAL - BOSS FIGHT
You will find yourself indoor again. Ra's will tell you that you have done will and to find him and collect your reward.
Exit through the door and up the stairs. Talk to Talia Al Ghul. Ask hem where Ra's is. She will say your final challenge awaits you through that door.
Enter the chamber. Ra's al Ghul will give you your final challenge. He will tell you that you have to kill him and replace him as the head of the Demon. But you refuse to kill anyone. After a cutscene you find yourself outdoors, and you must now fight Ra's Al Ghul. This is a boss fight.
He will summon several ninjas. While you are fighting them, he will launch special attacks at you. He will then turn into a large demon and fire blades and shurikens and you. Make sure to dodge and avoid them at all costs. Use your REC electric gun to quickfire electrical charges at him. Once you have lowerd all his health, he appears back in humanoid form and attacks you. Counter his attacks. There will be another cutscene. Talia al Ghul will tell you to accept your destiny and kill her father so that you and her can rule the world. You tell her you cannot do that and she tells you to prepare to die.
Back outdoors, a big group of enemies appear. When they attack you as a group, do a group counter. Defeat them. Once Ra's transforms again, quickfire the electric charges at him. When he finally weakens and goes back to humanoid form, counter his blade strikes and beat him down with a flurry of punches.
Ra's will now take his own daughter, Talia, hostage and threaten to kill her if you do not kill him. He wants you to lead the League of Assassins.
Pull out the remote controlled Batarang. Program it for reverse mode. Reverse Batarang is a pre programmed remote batarang that loops back on itself to hit an enemy from behind, leaving them dazed and confused. Program the remote Batarang to take down Ra's Al Ghul. Lock on Reverse Batarang Target and throw it. Then jump and charge Ra's to knock him out.
Take a sample of his blood. You are getting closer to finding the cure!