Best legendaries for a legendary heavy deck?
For a rush deck, Leeroy is excellent as a finisher. Sylvanas, though a bit pricey compared to other cards, can fit into a rush deck but she can also be a dead card many times.
I know one of the YouTube personalities "WoWCrendor" (who is not necessarily uh... great at the game) was using a mix of Murlocs and Legendaries to make some decks. It might not be the most competitive*, but if you want silly fun you might look into it.
*(This is an understatement.)
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