Usage patterns
〈事〉がクライマックスを迎えるfor a story or event to reach its climax
The drama reached its climax in the final episode.
〈事〉がクライマックスに達するfor something to build up to its climax
The match reached its climax in the second half.
クライマックスシーンthe climactic scene (of a movie, story, etc.)
You can't watch the movie's climactic scene without crying.