True or false?

[Sora341]

So in CoM, Ansem appears to Riku a number of times. At one point Riku actually defeats Lexaeus while in dark mode. And when he speaks, his voice is overlaid with Ansem SoD.

Also Riku is shown shrouded in darkness, and Riku claims that darkness that foul could only be Ansem..

But in the end of the game, we see that Ansem the Wise was actually setting up Riku to face his own darkness. by pretending to be the seeker of darkness.

Did the real Ansem Sod ever show in CoM? Or was it always an illusion?

 

[Oracle Spockanort]

It was both Ansem SoD and Ansem the Wise/DiZ.

The first time we see Ansem SoD was actually AtW/DiZ pretending to be SoD in order to guide Riku. The times after were the real Ansem SoD who still remained in Riku's heart, festering within the Darkness Riku was afraid of and trying to keep at bay.

AtW/DiZ appears to Riku later on in the game as SoD again, but Riku sees through the facade and AtW/DiZ reveals himself.

Then after that point it is SoD again as Riku faces him again.

 

[Sora341]

So Riku defeats him. Why does he still linger in his heart so pungantly?

 

[Gram]

So Riku defeats him. Why does he still linger in his heart so pungantly?

It's thought to be because of Xehanorts ability to leave seeds of his heart in others. But whether it just a seed of Xehanort or Xehanort's heart (aka Ansem) itself, it's simply due to how strong of heart Xehanort is.

Even though ones body does indeed die the heart always lingers on and goes into either sleep or KH after natural death.
What that means is you can't just do inside and defeat Xehanort and be magically free, you have to expel him in some way.

When Riku got hit by that light from the exploding encoder in KH2 this is what happened, Xehanort/Ansem was expelled from Riku finally freeing him.