the explosion essentially ruined -- or , rather , overpowered -- 
(ROOT (S (NP (DT the) (NN explosion)) (ADVP (RB essentially)) (VP (VP (VBD ruined)) (, --) (CC or) (, ,) (ADVP (RB rather)) (, ,) (VP (VBN overpowered))) (: --)))
(ROOT (S (NP (DT ) (NN )) (ADVP (RB )) (VP (VP (VBD )) (, ) (CC ) (, ) (ADVP (RB )) (, ) (VP (VBN ))) (: )))