Who produced cubist paintings that looked like he had shattered reality and reassembled the fragments?

Answer is: Pablo Picasso.

Pablo Picasso (1881 - 1973) was a Spanish painter, sculptor, poet ...

He is cofounder the Cubist movement with Georges Braque.

Cubism is an early-20th-century art movement.

Example is Guernica. Thia painting is a late example of Cubism in a more realistic style.

Pablo Picasso was the one made that art