Quoting: SevenLeg
You probably know best, but as fan of neither team I think LAK should do it. You guys have a lot of offense coming up and with one of Byfield/Stutzle, Vilardi seems expendable and Sergachev solidifies your top 4 for years to come
That's assuming everyone works out, and that's far from guaranteed. Turcotte had a poor season in Wisconsin this year, and none of the other center prospects in the system project to be better than middle-six (Kupari, Madden, Thomas, etc.). If the Kings do as I suspect they will and take Stutzle over Byfield, they're going to need Vilardi as a 1C/2C option as Kopitar ages and moves down the depth chart.
If the Kings were an offensively capable team in the past, then I would be more inclined to make this type of trade. However, the Kings are fairly decently stocked at LHD, with Bjornfot, Anderson, Clague, MacDermid, and Hults all near NHL ready. Sergachev would be an immediate upgrade over any of them, but not at the expense of the best center prospect in the Kings system.
I would say that one or two of Kupari, Madden, and Thomas are now expendable, but neither of Vilardi or Turcotte are.