I enjoyed this a lot! Very fun characters, and they synergize very well with each other's abilities. I think Ralsei was my favorite; he's adorable, and I spent as much time playing him specifically as I could.
The dialogue was also a lot of fun, and a neat change of pace from the silent narrative we typically get regardless of who we play; so far, the Fun Gang is the only character mod I'm aware of that does such a thing, though I'm sure there are others that I just haven't been introduced to yet. If I have any complaints about it, though, it's that it feels a little incomplete in places. Some of the boss battles don't have any, so narratively I was left wondering why the characters are only speaking up some of these times and not others.
I like that the creators exercised restraint in certain regards; so many character addons, it feels like literally everyone gets a Super state. Not these ones. Would it have been fun? Yeah, probably; I can't deny that Super states are fun, which is probably why everyone puts them into their characters whether they were supposed to have one or not, if the character in question was canon. But it's nice that these three got the "normal" treatment regardless; despite coming from a completely different game, this is one thing that makes them feel like they belong here.
I've probably already said too much, but this addon is going on three years old as of this writing. Suffice to say, it's a good addon, and was absolutely worth playing. Play it yourself! For everything I did talk about, there's more I didn't!