Choco/Mog is indeed a weak summon, but I used it to defeat that Wall enemie in the Temple of Acients when I first went true the game. Really great was that, cause I only had a summon Shiva, Bahamut and Choco/Mog. The Bahamut summon didn't work, Shiva only one time and Choco/Mog helped me. Yeah, that really was very close.