The point is, the real Ansem was a good guy, not the one controlling Riku.
Riku-Ansem is identical to Ansem, which is the Heartless of Xehanort.
Xmnas is Xehanort's nobody and Ansem is Xehanort's heartless. So, basically they are all the same guy. Ansem already tried to take over Riku's hearts so they already have a score to settle with him.
Riku didn't pretend to be Ansem. Riku's heart was engulfed by darkness and Ansem lays dormant inside of him. When Riku 'submits' to the darkness, he takes Ansem's appearance and must wear a blindfold to cover it up. (hence the blindfold we see throughout Kingdom Hearts II and Kingdom Hearts 358/2 Days)
Ansem is controlling Riku's body while Riku still has very little control of his heart.
It depends on who "Ansem" is, because there are really 3 different "Ansem"':One is the real Ansem the Wise who disguises himself as DiZ because the other 2 Ansem's take his identity.One fake "Ansem" is Xehanort's Heartless, who calls himself Ansem but is really the antagonist of KH1.The third "Ansem" (the second fake Ansem) is Riku-Ansem: after Riku takes off his black blindfold at Memory's Skyscraper in order to gain enough dark power to defeat Roxas, he permanently turns into Riku-Ansem, who is really Riku but now looks like the other fake Ansem and has more combat power.Since all Nobodies are created from the creation of Heartless, Xemnas is the Nobody of Xehanort's Heartless, Ansem.
Yes, the real Ansem (Ansem the Wise) was a good guy. He was just confused with the idea of getting revenge on his apprentice, Xehanort. Xehanort had stolen the idea of studying and using hearts for darkness, which turned Xehanort into a Heartless called Ansem and created a Nobody named Xemnas. Until Ansem the Wise met Riku, Ansem thought revenge was the only way. When he saw that Riku released his inner darkness to help save his friends, Ansem realized that revenge is wrong. Since then, he had been helping Riku fight the darkness.
SPOILERNo. The first Ansem was Xehanort's Heartless impersonating Ansem. The second Ansem was Riku, who released the darkness in his heart to change himself into a man that looked like Ansem. Riku did so to be able to wield the power of darkness and protect Sora without darkness consuming him.
No Riku is blind but not really. The only reason Riku has the blindfold on is because since he was consumed by the darkness in Kingdom Hearts 1 he has to keep himself in the dark or his true form will come out which is the body and voice of Ansem who is actually Xemnas' somebody who is actually Xehanort and NOT Ansem the Wise.
Ansem/Maleficent convinves Riku to give into darkness so that he may obtain dark powers which he thinks he can use to regain Kairi's heart. However, Ansem is really just using Riku as a host. So technically, he doesn't turn into Ansem; the two are still different people.
Hm, I would say 1. Let's review the four "Ansems": 1.) There's Ansem the Wise, aka Diz, the "original" Ansem. 2.) His heartless is also called Ansem. Heartless Ansem was the only one who claimed to be the original Ansem, so that's why only he is really an imposter. 3.) Ansem's nobody, Xemnas (Ansem remixed + an x), looks almost exactly the same as heartless Ansem, but this one does not claim to be anyone but what he is. 4.) But if you really want to split hairs, you could count Riku as one of the "Ansems" after his appearance was transformed to look exactly like heartless Ansem. He changes back later on. Convuluted, no? :)
Riku-Ansem looks like the fake Ansem.
There was no Ansem in Kingdom Hearts 358/2 Days. However, there was Riku-Ansem (Riku's dark side) but Riku was still a good guy. In the other games, Ansem the Wise is a bad guy.