I have searched and found nothing relevant (so if there is I apologise), and I am kinda uncertain if this is the right place to post this. So if it is not in the right place, I apologise again.
There may be some inaccuracies, as it was hard to catch what they were saying. A friend helped with with some of the kanji (thanks to their Kodansha Kanji dictioanry).
Personally, I think this was quite an easy scene to translate, except for the part where Zack appears. Some parts were harder then other, especially with some of the words with repeating syllables that Sephiroth uses. Cloud's language was quite simple, and easy to understand, whereas Sephiroth had a much richer quality to his lines.
I have excluded the part with the Zack cutscene, as I could not work out a large portion of it.
Also, I think I got the kanji for Geostigma right (星痕症侯群 Seikon shoukougon = Earth/Star Mark Syndrome). If it is wrong, please feel free to correct it.
Orange = Kadaj
Purple = Sephiroth
Black = Cloud
Yellow = Marlene
Boku no riyunion misete ageru yo.
My reunion, I will show you.
It has been a while, Cloud.
Seikon-wo nakushitano ka? Zannenda.
You have lost your Geostigma? That's a shame.
Ittai nani ga nozomi nanda.
What do you want?
Seikon-wo yadoshita shisha no shinen.
Geostigma will conceive the thoughts of its' victims.
Sore-wa raifusutoriimu totomo ni hoshi-wo meguri.
Together with the Lifestream, it will surround the planet.
Yagate hoshi-wo shinshoku suru.
Before long, it will corrode the planet.
Watashi no nozomi-wa na kuraudo.
My desire is, Cloud
Kono hoshi to funeto shite uchuu no yami-wo tabisuru koto da.
Using this planet as a vessel, I will traverse the darkness of the universe.
Katsute haha ga soushita you ni na.
Just like my mother long before.
Yagate warera-wa atarashii hoshi-wo miidashi.
Before long we will find a new planet.
Sono chi de kagayakeru mirai-wo souzou suru.
On that soil, we will create a shining future.
Kono hoshi-wa dounaru.
What will become of this planet?
Saa, omae shidai dana
Well, that's up to you.
Hou?! Nani ga omae-wo tsuyokushita.
Oh?! What has made you so tough?
Anta niwa iitakunai ne.
I dont want to tell you.
Omae-he no okurimono-wo kangaeita.
I thought of a present to give to you...
Shall I give you despair?
Hizamazuki yurushi-wo kou sugata-wo misete kure.
Kneel and show me yourself begging for forgiveness.
Ano toki no itami-wo oboeteiru-ka? Kuraudo.
Do you remember the pain from that time, Cloud?
Ima futatabi wasurerarenu itami-wo kizamou
Now again, I will engrave the pain so you won't forget.
Omae no motto mo taisetsu-na mono-wa?
Whats the most important thing to you?
Sore-wo ubau yorokobi-wo kurenai-ka?
Will you give me the pleasure of taking that away?
~Zack & Cloud Cutscene~
Aware dana anta-wa nani mo wakatteinai
It's pathetic. You don't understand anything.
Taisetsu ja nai mono nankanai
There are not any things that are not important to me.
Omoide no naka de jitto shiteite kure
Stay firmly within my memories.
Watashi-wa omoide niwa naranai sa.
I will never become a memory.