Wachtell, Lipton, Rosen & Katz; Paul, Weiss, Rifkind, Wharton & Garrison and Vinson & Elkins worked a massive $26 billion energy deal, while Skadden, Arps, Slate, Meagher & Flom and Latham & Watkins both advised on at least three multibillion-dollar deals, in one of the most active weeks in dealmaking in the last two years.