I haven't watched too much Xenoglossia
I strongly recommend you to do it!
Xenoglossia is a lot better than
Evangelion! I just don't understand, why people compare them!
her personality is a complete 180 from the Chihaya we know from the games.
I think Chihaya (in general) is a very serious and purposeful person, it can be either good or bad. In other words, Chihaya-Master loves Imber as much as Chihaya-idol loves singing. What set them apart is their past, even despite the death of Chihaya-idol's brother, she can say: "I had a happy childhood" and Chihaya-Master can't.

I think Chihaya-Master is Chihaya-idol's dark side, an example of what can happen if a person found oneself in a wrong place in a wrong time. Things are the same for Yukiho-Master and Makoto-Master.
a Lucky Star character (Hiyori)
I like her songs! It is very funny to imagine that Chihaya-Master sings them!
By the way, Kaori Shimizu is a great singer! I even made an AMV about Chihaya-Master with her song! (I posted a link in my topic, the AMV is called "Endless journey ~To my friend~")kind of like the Hulk is with Bruce Banner
Haruka:
- Chihaya-chan, let's go shopping together!
Chihaya (with Kaori Shimuzu's voice):
- Wha-at?! How dare you to call me like that?! I am Chihaya-sama!!! I'll kill you if you mistake again!!!
Haruka:
S-S-Somebody, s-s-save m-m-me...
Chihaya (with Asami Imai's voice):
- Haruka-san, why are you so scared?