Character: Clover

Clover was a professor and scholar at the Tree of Knowledge and was affiliated with the Scholars of Ohara, an organization that was trying to uncover the truth of the Void Century inscribed on the Poneglyphs.

Clover was a kind and caring man, as he did not consider Robin to be the monster every other citizen of Ohara feared and mocked. He allowed her to study the books in the library and eventually graduated Robin in archeology. However he did not let her study the Poneglyphs, in order to protect her from the World Government.

Professor Clover's skills included the ability to read the Poneglyphs, making him one of the few people that could read about the Void Century and also find out the exact locations of the ancient weapons.

He died when the World Government found out about Ohara's research on the Poneglyphs and sent team CP9 to find out exactly what they knew. When Clover spoke almost everything he knew, the Gorosei ordered Spandine to kill him.

He was shot and mortaly wounded by Spandine, and died later with the bombardement of Ohara.

Source: http://onepiece.wikia.com/wiki/Clover