This sentence means that even if you have unparalleled skills or power, you cannot protect the one you love.

This sentence comes from Miyamoto Musashi's line in "Glory of the King", which expresses a kind of helplessness and regret. Even if you have powerful abilities, sometimes it is difficult to protect your beloved people or things. This It may be because some things are beyond one's ability, or it may be because there are unpredictable risks and accidents.