Until recently I thought that the song names "Catenae Fortunae" & "Eternal Blessing" were made up, but as it turns out some of songs from Pandora's Tower do in fact have official titles. Apparently, Nintendo of Japan had some sort of mobile service thing called Nintendo Mobile (任天堂モバイル) that distributed content like ringtones and such and at one point released a small handful of tracks from Pandora's Tower. However, Nintendo Mobile's service ended in March of 2013 as shown here. https://www.nintendo.co.jp/etc/nintendomobile/
Learning this I searched online to find any details I could regarding these official titles and after some digging I finally managed to find some sites that featured some information about them. Unfortunatly I don't speak Japanese so I had to rely Google Translate to fill in a couple of the blanks which can often be inaccurate, so just keep that in mind.
https://www21.atwiki.jp/gamemusicbest100/pages/2873.html
Composer: 小原たかゆき (Takayuki Kobara) Arranger: 小原たかゆき、廣瀬祐一、吉川哲也、出川和平 (Takayuki Kobara, Yuichi Hirose, Tetsuya Yoshikawa, Kazuhira Degawa)
- Name: Catenae Fortunae (Dies irae) / *Original Song: Dies irae from Requiem by Giuseppe Verdi / *Usage: Opening
- Name: 第4番「ボヘミアの森と草原から」 *Translation: No. 4 "from Z českých luhů a hájů") / *Original Song: Z českých luhů a hájů from Má vlast by Bedřich Smetana / *Usage: In the Thirteen Towers
- Name: 外僕達の邪悪な踊り / *Usage: 外僕戦 **Not sure what the title translates to, Google Translate gives "Outside our wicked dance," but I'm skeptical on the accuracy of that. I think the usage says that it's the Servent (as in Servant Beast) battle theme, but I could be wrong about that.
- Name: ボス戦 男声ver (暗き深淵の声 主たちによる男声合唱) / *Translation: Boss Battle Male Voice Ver. (Male Voice Chorus by *can't translate this part properly myself, Google Translate gives "the voice of the dark abyss"* / *Usage: 1~5 towers main battle
- Name: ボス戦 女声ver (暗き深淵の声 主たちによる女声合唱) / *Translation: Boss Battle Female Voice Ver. (Female Voice Chorus by *can't translate this part properly myself, Google Translate gives "the voice of the dark abyss"* / *Usage: 6~10 towers main battle
- Name: ボス戦 男女混声ver (暗き深淵の声 主たちによる混声合唱) / *Translation: Boss Battle Male & Female Voice Ver. (Male & Female Voice Chorus by *can't translate this part properly myself, Google Translate gives "the voice of the dark abyss"* / *Usage: 11 & 12 towers main battle
- Name: 安息 / *Translation: Rest / *Usage: Observatory
- Name: 麗しのグライアイ / *Tranlastion: グライアイ is Mavda's Japanese name, I think "麗しの" means "Beautiful" / *Original Song: Amarilli, mia bella by Giulio Caccini / Usage: Mavda's theme *Seeing as it's an arrangement of Amarilli, mia bella and how "mia bella" means "my beautiful" I'd say that the best translation would be "Mavda, mia bella."
- Name: 永遠の恵みよ(愛の夢) / *Translation: Eternal Blessing (Liebestraum) / Original Song: Liebestraum No. 3 by Franz Liszt / Usage: Song by Yucca, S End http://www.nicovideo.jp/watch/sm14655067
I'm not familiar with the vocalist, but I'm presuming that it's this person here, her work does seem to sound similar. http://vgmdb.net/artist/12232
- Name: 永遠の恵みよ(愛の夢)アカペラver. / *Translation: Eternal Blessing (Liebestraum) A cappella Ver. / Usage: Not sure what 劇中歌 means but the A cappella version would be the one where Elena sings with no instrumental accompaniment.
- Name: 永遠の恵みよ(愛の夢)ピアノ伴奏ver. / *Translation: Eternal Blessing (Liebestraum) Piano accompaniment Ver. / Usage: Used in A & B End http://www.nicovideo.jp/watch/sm14658852
- Name: 永遠の恵みよ(愛の夢)ラスボスアレンジver. / *Translation: Eternal Blessing (Liebestraum) Last Boss Arrange Ver. / Usage: Final Boss Battle http://www.nicovideo.jp/watch/sm14659167
- Name: 悲愴 / *Translation: Sadness / Original Song: Pyotr Ilyich Tchaikovsky's Symphony No. 6 / Usage: Used in D End (I should mention that it's used at some other points in the game too, I believe that the first time is when Elena has to eat Beast Flesh for the first time.) https://www.youtube.com/watch?v=QKv_GmigRIM
I found a second site (I think it may be the Japanese Wiki) which listed more titles, however many of them seem to be fan-made since it states that only the names in Bold font are official titles, those being the same as the ones listed on the previous list. The only ones I see in Bold that aren't featured on the other one are "十三訃塔" (I think it's "The Thirteen Towers") / "十三訃塔中層" (I think it's "The Thirteen Towers Middle Layer") / "0号へのレクイエム" (Requiem for No. 0 *I'm pretty sure No. 0 became "Zeron" in the English dub) Also I noticed the "Sadness" track is not bolded here despite being included in the other one, since the product is no longer avaible I can't 100% confirm which tracks were or were not included. https://wiki.grovyle.net/pandora/index.php?%E5%B0%8F%E3%83%8D%E3%82%BF
The site also has lyrics for the Latin songs, thoose being the Opening, Boss themes, and the Final Zeron Chase theme. https://wiki.grovyle.net/pandora/?%E3%83%A9%E3%83%86%E3%83%B3%E8%AA%9E%E8%A7%A3%E8%AA%AD I'm uncertain at this time if the site lists the lyrics for Eternal Blessing anywhere or not, though I did find another site listing the Japanese lyrics for Eternal Blessing, they seem to be the same as the ones already listed on this wiki which is good at least. http://urauraomote3.blog108.fc2.com/blog-entry-409.html
I'll probably try asking on Reddit at some point to get some help with the title translations and such. On another note, I was curious as to where the name for Zeron's true form "Bado Shub-Niggurath" came from. Is it listed as such in the Japanese guidebook or something? I noticed that the artwork for it on Creativeuncut lists it as "Bado" though I've no idea what that means, however I am aware of where the name Shub-Niggurath is taken from as I'm an avid Lovecraft fan. http://www.creativeuncut.com/gallery-20/pt-bado.html