獅子奮迅[shishifunjin] being irresistible
疾風迅雷[shippuujinrai] with lightning speed
迅速[jinsoku] quick
迅雷[jinrai] thunderclap
奮迅[funjin] impetuous dash forward

無常迅速[mujoujinsoku] the (fast) pace at which life passes, and thus the nearness of death
獅子奮迅の勢い[shishifunjinnoikioi] irresistible force
迅速果断[jinsokukadan] quick and decisive
迅速果敢[jinsokukakan] quick and decisive