Being a (semi) completist gamer, I just HAD to have the last extra character in Disgaea 3: Absence of Detention unlocked.
I'm actually done with the game: finished the main story and killed the final boss (which was tedious). Yes, there is still this one final, final boss in the "Land of Carnage" but that really requires hours after hours of mindless grinding (getting characters up to Level 9999) but I'm NOT that crazy. I've done enough grinding for now. Anyway, so there are three special characters that can be unlocked (without too much grinding): Pleinair, Angel/Celestial Host and Aramis. While the first two were reasonably easy, unlocking Aramis was a Nightmare.
The challenge here is to finish TEN battles within 145 moves/commands. In my first few tries, I had, like, already 120 moves and I was only in the third battle. Anyway, after much persistence (and good luck, since some of the maps I had was REALLY easy in my final attempt), I was around 140-145 moves when I had ONE final Gatekeeper (in battle no. 10) to destroy .... but she just would NOT die!!! Then I went over 150 moves, I thought I'd wasted all that (hours of) effort and was on the verge of having a teary breakdown ... but when the gatekeeper was finally killed, I got a 20 move BONUS!!! Hurrah!!! Unlocked!!!
Now I feel ... completed.