You must get the wedding pendant first before you can unlock Gadiel to do this acheivement. Firstly you must do
and then after defeating the boss you get the wedding pendant. To keep the items for the next playthrough you must either finish the game or die.
At the start of the game choose a character and then go over to the second guy with white hair and talk to him. It will spawn you as Gadiel with a whip. Then press in order
and then you are ready to start.
Go through the first teleporter and skip the first act by hitting
and then
The Statue you are looking for is somewhere in the second act and its in a random location every time. Once found you go to it and hit
which will break the statue and net the achievement.
If for whatever reason the statue is somewhere you cannot seem to access you can try using his grenades on a thin wall/floor with
If it is a jump you are struggling to make you can also back out to the main menu and try again.