Sure, but as I have not finished reading through in detail the whole game yet, I will just provide a rough explanation for the endings. I highly recommend the beginning and the middle portion of the game as well, so I will not touch on those here.
1st Bad End: Marina in her corrupted fox loli form (which also appeared in Exstia Parallel 1) corrupts Spica (TS Soma, but she came from another reality, so it is separate from the Soma in this game) into a fox demon, and both takes turn to assault Soma, which then converts Soma to a fox demon as well. The 3 fox demons defeated Jerishgiru (main villain of the game, also introduced in the offical webpage), and continues to protect(?) the streets by killing other demons that appears...
2nd Bad End: Marina undergoes reconstruction, turning into an android and being mass-manufactured by Jerishgiru to be sold to others. Poor Soma who is being kept alive by Jerishgiru is now only left with his head and neck, being forced to watch his lover commit acts with others...
3rd Bad End: After Marina in her Luxuria form (which first appeared in Exstia 3) feels denied of her existence, she merges with all the other forms/realities of her, turning into Exs-Marina (if you look at CGs, it is the one with white hair and has both white and black wings). She corrupts Spica into her Luxuria form, Spica then assaults Soma and assimilates Soma into herself, turning into Exs-Soma. The both of them wander across different timelines and worlds, collecting all the Exstias...
I won't spoil the good ending!
For anyone who can afford it, please do support Lusterise by purchasing the game..! I personally think that it is a masterpiece.