The kindness and enmity between the two families lasted three generations.
Tips
culture
恩仇 is a wuxia (martial-arts fiction) signature word. The genre revolves around 恩怨 / 恩仇 — heroes are defined by whom they owe and whom they must avenge. Jin Yong's classic 笑傲江湖 lives entirely on this dynamic.
memory
恩 'kindness' + 仇 'hatred / enemy' — opposites yoked together to capture the full ledger of obligations a person carries.