So I bought Disgaea D2 today, and so far, I'm having a blast. 
The game has veered away from Disgaea 3 and 4's system of learning abilities and such and brought back Disgaea 1 and 2's mentor and weapon mastery, with a few added tweaks.
For example: The mentor/pupil system has been changed so that the PUPIL is the one learning spells and abilities from the mentor. And you can simply assign him/her to whoever you want instead of having to make sure they're created by a specific character.
Evilties have made a comeback, but this time, the innate evilties are assigned according to a character's personality, so when you create a character, the evilty you get is dependent on which personality you choose. However, you can change the evilty whenever you want, so you can switch up each character's evilty to suit your team's needs.
There's also a new likeability system, which makes it so that the more two characters like each other, the more likely they can do stuff such as one of them can protecting the other from damage, which is really good for tanking and protecting my weaker units.
Magichange has been replaced with mounting, which is essentially the same except it seems like you can stay on the mount indefinitely and the mount takes the damage for the person riding it.
There's quite a few other features, but I won't get into them right now.
As for the story and characters, I've only just beaten the first chapter, and so far I'm liking it. Laharl and crew are the main cast again and they're still as funny and charming as ever. (I will admit, to me it felt like Laharl's VA sounded a bit off at first, but it seems like as the game's first couple of hours went on, she started to settle back into the role)
Also, the game's first boss:
A gargoyle with a Russian (I think) accent. BADASS.
So yeah, really enjoying the game so far. To those who have also picked up the game, what do you guys think of it so far? And if I got anything wrong, go ahead and correct me.
The game has veered away from Disgaea 3 and 4's system of learning abilities and such and brought back Disgaea 1 and 2's mentor and weapon mastery, with a few added tweaks.
For example: The mentor/pupil system has been changed so that the PUPIL is the one learning spells and abilities from the mentor. And you can simply assign him/her to whoever you want instead of having to make sure they're created by a specific character.
Evilties have made a comeback, but this time, the innate evilties are assigned according to a character's personality, so when you create a character, the evilty you get is dependent on which personality you choose. However, you can change the evilty whenever you want, so you can switch up each character's evilty to suit your team's needs.
There's also a new likeability system, which makes it so that the more two characters like each other, the more likely they can do stuff such as one of them can protecting the other from damage, which is really good for tanking and protecting my weaker units.
Magichange has been replaced with mounting, which is essentially the same except it seems like you can stay on the mount indefinitely and the mount takes the damage for the person riding it.
There's quite a few other features, but I won't get into them right now.
As for the story and characters, I've only just beaten the first chapter, and so far I'm liking it. Laharl and crew are the main cast again and they're still as funny and charming as ever. (I will admit, to me it felt like Laharl's VA sounded a bit off at first, but it seems like as the game's first couple of hours went on, she started to settle back into the role)
Also, the game's first boss:

A gargoyle with a Russian (I think) accent. BADASS.
So yeah, really enjoying the game so far. To those who have also picked up the game, what do you guys think of it so far? And if I got anything wrong, go ahead and correct me.