Riku entered through his dark portal, and suddenly appeared in a primitive village. No roads, no cars, and no lights.
But all that mattered to Riku was the mission.
On Destiny Islands, Riku had a vision of a Dark Sword that the Heartless were going after. Without telling Sora or Kairi, he left using a portal.
He would destroy the sword so the Heartless wouldn't gain it, and then return to his home.
Walking through the village, he sensed the presence of Heartless. Quickly, Riku found a Heartless wielding a scythe, battling some sort of..Samurai.
Riku stabbed his Keyblade through the Heartless' back, instantly killing it.
"Thank you," the Samurai said. "Who are you?"
"I am Riku," said Riku. "And you…?"
"My name is Mitsurgi. What is that odd weapon you carry?"
"….It's called..a…Keyblade."
"What an odd weapon….Are you familiar with the creature you have just slain?"
"They're known as the Heartless."
"I have never seen such a foul creature before. Why are they here?"
"I'm guessing the cursed sword…," Riku said.
"The Soul Edge."
"If you ever see those creatures again, kill them at once," said Riku.