very short-tempered and often tended to overreact to certain things. he was not above enjoying a good fight, and he often blew up his opponents in a very brutal fashion. Deidara's most distinctive trait, however, was his love of art. 
During his partnership with Sasori, Deidara usually showed a cool, and relaxed attitude, never losing his smirk even while fighting an intense battle or when being blamed by his partner. However, his personality seemed to change to some extent after being partnered