LordSpearion (He also has many shields, and the variant of Nihil Stella that is better at draining shields. (Once again, Kodename's Kannons is OP)
EDIT: Tested only the Titanic Class vs. the Mother of Spears. The Titanic Class's shield spam prevented the DSSL from tearing its front weapons down, and the Mother of Spears was quickly torn away by the Nihil Stella and nukes. (you did underestimate its power...)