Forum:DED question

Ok, if my opponent uses DED's effect to remove something from their graveyard. I can chain Solemn Judgment to the summon right? When would I have to activate Solemn Judgment? Second if my opponent chains MST on DED's effect, to destroy Solemn Judgment..would I still be able to chain Solemn Judgment? I feel like no..cuz the timing is off..