"Leaped into the breach" is a powerful phrase that evokes imagery of bravery and heroism. However, there are several synonyms that can be used to convey a similar meaning. "Stepped up to the challenge" is a phrase that suggests taking responsibility and demonstrating leadership. "Filled the void" or "took up the mantle" both imply the act of joining a cause or taking on a difficult task. "Rushed to the fore" and "charged into action" both emphasize the sense of urgency and determination needed to face a challenge head-on. No matter the choice of words, the underlying message is clear: in the face of adversity, one must summon the courage to step up and make a difference.