This is what we found on Wikipedia regarding the GZA:

Gary Eldridge Grice (born August 22, 1966), better known by his stage names GZA ( JIZ-ə) and The Genius, is an American rapper. A founding member of the hip hop group Wu-Tang Clan, GZA is the group's "spiritual head", being both the first member in the group to receive a record deal and being the oldest member. He has appeared on his fellow Wu-Tang members' solo projects, and has maintained a successful solo career starting with his second album Liquid Swords (1995).

His lyrical style often dismisses typical rap story lines in favor of science and wide-ranging philosophies and has been characterized as "armed with sharp metaphors and a smooth flow". An analysis of GZA's lyrics found that he has the second largest vocabulary in popular hip hop music. He teamed up with an education group to promote science education in New York City through hip hop.