FeroxUltrus 
"[@Darth Sonic":](/1359992#comment_5882571
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I should look up these elves of which you speak, but if you want a spoiler that is in book 1. Adagio plans to have their gemstones replaced as their new ones which are earthen sirens break in the return trip. From there she will seek out to enslave every pony till they reach canterlot and have more power than even the Princesses. There will be a whole lot more happening as her plan is sought to be made reality, so character growth, conflict, and revelation will reboirnth Adagio and the others with the help of Sci Twi's innocence.
I should look up these elves of which you speak, but if you want a spoiler that is in book 1. Adagio plans to have their gemstones replaced as their new ones which are earthen sirens break in the return trip. From there she will seek out to enslave every pony till they reach canterlot and have more power than even the Princesses. There will be a whole lot more happening as her plan is sought to be made reality, so character growth, conflict, and revelation will reb