Akinator Lite for Android is an app that will guess ANY character your thinking of o_o like seriously....it guessed
Mashiro from Bakuman
Cole from Infamous
Alex from Prototype
Dokuro from Bludgeoning Angel Dokuro Chan
Light from DeathNote
Ragna the Bloodedge from BlazBlue
Shinji Ikari from Neon Genesis Evangelion
It asks you questions so it makes sense but I still find it amazing somehow o_o Try it out if you can! Akinator Lite is free and gives you 10 character guesses a day and theres a paid version that gives you unlimited.
After playing around with it, I figured out how it works. Rather than having a preset database, it uses the answers the user comes up with to tag characters with certain attributes that are fulfilled when someone answers the questions. The database had no entry on Satsujinki from Melty Blood/Tsukihime...so when it eventually got it wrong, it had me create the entry for him and used my answers as his tags so when people sought him out, he would pop up. Sorta kills the magic of it but still pretty intriguing ;__; If you know who Satsujinki is try and get him to come up o.o it'll probably take more than 1 try for the genie.