What does Legend mean?
A modern word-name taken straight from the English word 'legend' (ultimately from Latin 'legenda', 'things to be read'). It is an aspirational virtue/word name with no older history as a personal name.
What does King mean?
The English vocabulary word 'king' (Old English 'cyning') used directly as a given name. A transferred surname/word-name rather than an etymological 'king' name from another root.