Easy E was a horrible rapper and writer. Cube wrote all his shit and in the studio Easy sucked in rapping, always messed up, took like 100 recuts to make a song.
Im not sure if Nas has a ghost writer, but i know he ghost writes for peeps. When he was in the Firm, he wrote all of Foxy's lyrics. He ghost wrote for Will Smith on the song 'Miami'.
B.I.G. was and still is Jay-z's ghost writer...
Ea-ski needs a ghost writer, his 16's ruins a song....