Lilligant is completely awful, and I say that as one of my all-time favorite Grass types. Venusaur has significantly higher stat coverage, after one Growth it can sweep entire teams, and as if that wasn't enough also counters Heatran provided you can bait out Earthpower instead of fire blast. Gyarados can't kill you unless it runs Bounce, but choic'd variants make avoiding it much easier. if it's DD you're in the same boat.
Speed is not an issue here, Clorophyll grants you double speed, only a very small percentage of pokemon (Ninjask) can easily top that. Venusaur is also an excellant mixed attacker, and prevents you from being walled off as easily as Lilligant can. Not to mention Lilligan'ts entire movepool consists of Grass, normal, and hidden power. Very weak coverage.
Victreebell outperforms Lilligant in every way shape and size save for being slightly less bulky (If you're running quiver dance) It also has acesss to Weather Ball, which does absurd damage. It also reliably counters Politoad via Leaf Storm, and if I recall correctly can even run Sucker Punch, although admittedly it's not quite as useful imo as HP-Ice.
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