Chapter 6--Through the Portal Mission Walk-Through
Unlock the bonus mission, Through the Portal, by completing Rikimaru's, Ayame's, and Tesshu's missions. You could also use the appropriate cheat code revealed in the cheat codes section of this game guide. Select Through the Portal from the game's main menu. You play as Rikimaru and aren't offered an item selection screen; instead, you're automatically provided with one health power-up, three caltrops, three shuriken, and one poison rice.
Bonus Mission--Through the Portal
When the castle collapsed, the only way to escape was to jump into the portal that Meiah fled into. Inside the portal is a separate universe--a world in which a large biotech pharmaceutical company created a deadly disease and sold the cure for a large profit. Many civilians could not afford the cure and died. The government's auditing of accounting procedures led to the unveiling of fraud, but the CEO bribed his way out of jail. You must punish the evil CEO.
Walk forward to the edge of the chain-link fencing on your left. There's a security guard around the left corner. Wait until he walks the other way before approaching him and performing a stealth-kill move. He could also be patrolling up the staircase; wait for him to come down if he's there. Ascend the staircase and wait for the next guard to move away from you. Approach him from behind and terminate him. Go left and into the doorway. Terminate the nearest guard that patrols around the right staircase. A second guard patrols on the left side around the wall. Go around this wall and outside. Look left while on the catwalk and drop down behind the guard below.
Turn around and spot a guard across the path; he lurks on the other side of a fence. You can't get through this fence, so look up and to the left to discover a high ledge. Grapple up to this ledge. Drop down onto the pipes and go right. Locate the small tunnel here. Crouch and crawl through. The tunnel leads into a parking garage.