Her Personality: 

Young one, when I look at you...I'm reminded of the human that fell here long ago...You have the same feeling of hope in your eyes.

Asgore's extended monologue if Flowey was killed in the previous run

While initially cast in a sympathetic light, Asriel admits at the end of the True Pacifist Route that Chara "...wasn't really the greatest person." Asriel states that Chara climbed Mount Ebott for an unhappy reason, and adds that Chara "hated humanity."

At the end of the Genocide Route, Chara behaves in a polite, formal, and terse manner. They thank the protagonist for teaching them the purpose of their reawakening: power. Chara informs that their determination woke them from death when entering the Underground.

If the protagonist refuses to destroy the world, Chara's eyes become wide, and rhetorically asks: "SINCE WHEN WERE YOU THE ONE IN CONTROL?", before destroying it with corrupt laughter. In the abyss, Chara is blunt, and criticizes the protagonist: "You want to go back to the world you destroyed."

After a second Genocide Route, Chara expresses confusion at the protagonist's "sentimentality," and states that they can no longer understand such emotions, implying that they, like Flowey, have lacked a SOUL, and thus emotions, since their death.

Ref: https://www.youtube.com/watch?v=qJWKGM_3lDk

Try To Imagine On What she Might Sound Like from The Actual Game She's From!🍫🌻