Cadmean victory 以巨大牺牲换得的胜利；付出惨重代价的胜利

【例句】
After the battle, the general said, “One more such Cadmean victory and we are finished.”
战后，将军说:“再来一次这样以极大牺牲换来的胜利，我们就完了。”

This army made Cadmean victory and defeated a much stronger army than them.
这支军队付出巨大牺牲战胜了比他们强大太多的军队。