Unlike the cards in the main set, Through the Ages cards do not become legal in Magic's Standard format (though they still are if the existing card was already legal there, of course), essentially just making them alternate art versions of those cards
You ideally need two impactful creatures in your graveyard for the opponent to choose from to mitigate the downside
Even then, winners were only given a promotional pack of cards, which had the chance of containing a Lillie Promo
RDW and Burn share a lot of the same DNA, but are definitely different decks
(All depending on your exact deck, of course.) Keep in mind the fact that you're playing a tribal deck, and adjust your play to optimize for that
However, it does have a weakness in its low HP of 30, but its ability to deal exponential damage overpowers that limitation