Brittle block breaks from one blow.
Normal block changes to brittle from one blow of small, normal and big ball and breaks from one blow of super ball.
Tough block changes to normal from one blow of small ball, changes to brittle from one blow of normal and big ball and breaks from one blow of super ball.
Strong block changes to tough from one blow of small ball, changes to normal from one blow of normal ball, changes to brittle from one blow of big ball and breaks from one blow of super ball.
Indestructible block.