While this has turned into a Lostgar disscussion thread, I think that Celebi prime will make a massive impact. When it comes to speeding energy attachment up, there is literally nothing that can do it better than Celebi Prime. Her Power lets you drop 4 Energy by T2, since that is unfortuneatly the average lifespan shes likely to have, unless you use three of those energy to power her.
And since Vilegar is such a dominant force, the Viability of SP decks is decreasing...So, it may be possible to hold on for quite a few more turns with Time Circle, allowing for Setting up at an ungodly speed. Grass/Psychic decks may become incredibly viable quite quickly, as will Grass and Decks that have those huge energy costs (for example, Legends. Just use Grass as your colourless, and you have your Legend useable by T2 without relying on luck).
Such decks would probably require an immense Energy Lineup to use...but I think it may be worth it. Perhaps this would work
7 Grass
9 Primary Type
2 Warp/Call
2-4 Interviewer's Questions
Regardless, I think Celebi has a lot of popularity coming to her, since her stalling ability coupled with the speed she brings certainly makes her a hugely powerful engine to set up with.
Magnezone Prime is also a bit interesting. While nowhere as good as Claydol, it is a possible draw engine to use. Lost Zoning your cards isn't a nice thing to have on the eve of Lost World, but it can take out threats without issue.
Overall, I'm really looking forward to this set. Its shaping up to be pretty cool