What made the 3rd Hokage so special that he could become a Hokage? I can't seem to figure it out..
The 3rd was said in the manga to be the strongest of all of the Hokages. He became Hokage when he was very young. He was also given the nickname, "The Professor", because supposedly he was a master of almost every jutsu. And most importantly, he had the "will of fire" where he would do anything and everything in his power to protect the people of Konoha.