Love
The historical record demonstrates love's capacity for civilisational disruption. The Trojan War, lasting ten years and destroying an entire city-state, originated from a romantic entanglement. The abdication of Edward VIII altered British constitutional history. Romeo and Juliet's ill-fated romance continues generating substantial theatrical revenue five centuries after composition.
Love's impacts compound across generations through family structures, inheritance patterns, and the genetic combinations it facilitates. Every human alive today exists as a consequence of love's successful operations across their ancestral lineage.
Ninja
Individual shinobi operations achieved targeted impacts: assassinations, intelligence acquisition, and the psychological destabilisation of enemy forces. The murder of Uesugi Kenshin, allegedly by a ninja concealed beneath his privy facilities, altered the balance of power in sixteenth-century Japan.
Yet ninja impacts remained geographically and temporally constrained. Their techniques could not be transmitted globally, and the tradition itself became largely obsolete following Japan's unification. The ninja's legacy persists primarily through entertainment media rather than continuing operational effect.