Butterfly Dance revolution. And I guess you could do a support set with sleep powder, leech seed, and substitute (and some attack move).
Lilligant's got the same problem as Seperior: a few gimmicks to make people remember her but otherwise a very limited movepool. In fact, she's got it worse than the snake. Her only special attacks that aren't grass are hidden power and hyper beam.
Butterfly Dance Sleep Powder Petal Dance HP Ground/Fire
With only 2 attacks you have to choose which Hidden Power you want for coverage, but unfortunately you have to accept that whichever one you don't choose will wall you with resistances. The big offenders are Heatran and Ferrothorn.
On the plus side, a boosted Petal Dance does good damage even against resisters.