に先立って => before; prior to ~ N2
に[先立「さきだ」]って/に[先立「さきだ」]ち/に[先立「さきだ」]つ => Before A occurs/takes place N2
Time, Situation
~んがため(に)/~んがための      => in order to ~ N1
んだが => Start the story N4
How to say the beginning
...たいんですが => want N4
How to say the beginning
んですが => opening the story N4
なにがなんでも => by any means... N3
Criticize
なにがなんでも => No matter how ... still (enthusiastic) N3
Will, intention
んがため => For the purpose of doing A N1
Reason, Result, Response
もの/もん/んだもの/んだもん => because; indicates reason/ excuse/ dissatisfaction N3
どんなに~うが => No matter what A, no matter how A N1
Miscellaneous
..は, ...が => Compare は and が N5
Compare