他们在古老的仪式上结为血盟兄弟，誓言永不背叛。

They became ___blood-brothers in an ancient ceremony, vowing never to betray each other.

虽然我们没有血缘关系，但在各个方面他都是我的生死兄弟。

Though we're not related by blood, he's always been my ___blood-brother in every way.