Image imported from derpibooru 
Original Description:
 
there will come a soldier, who carries a mighty sword  
he will tear your city down, oh lei, oh lie, oh lord
 
there will come a poet, whose weapon is her word,  
she will slay you with her tongue, oh lei, oh lie, oh lord
 
there will come a ruler, whose brow is wreathed in thorns  
smeared with oil like david’s boy, oh lei, oh lie, oh lord
 
oh lei, oh lie, oh lei, oh lei, oh lord  
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for my verse, Amore, Luna, and Celestia are the sisters, but Amore was turned to stone and shattered by sombra a long time before the events of the show. this is one of the events that led to the schism between Celestia and Luna that eventually led to Nightmare Moon, as Amore acted as a bridge between the two of them. The three of them represent the three main celestial bodies, as well as the three main pony species: the earth/earth ponies, the moon/pegasi, and the sun/unicorns. this is also how Cadnece is related to Luna and Celestia, as she’s the daughter of Amore. i’ll write something else up for this later but now this is all i’ve got.