Been toying around with this deck for a couple days now, and I have to say its pretty fun-
Celebi EX
Flygon
Dusknoir
Its definitely not Tier 1 but it can catch alot of the meta decks (and up and coming evolving meta decks) off guard. Having the 2 stage twos is a bit clunky, but with enough search it seems to function at a T3-4 set up level about 80% of the time.
Running Great Ball proves to be a great help as well, over Ultra Ball, since this deck- from what I can tell- cant afford much discard in order to operate well. Since you cant usually set up till later than your opponent, N is also a huge staple in this deck- allowing to short draw your opponent several turns (give or take) and rack up damage for Dusknoir to move around.