No I'm talking about the first part of the season 1 finale (Chibi Usa grows up in R, which is way later.) It's an episode where they die one by one, though if you only saw the English dub you didn't see the complete episode because they basically cut out all the death and turned 2 episodes into 1 episode.
Haha, it's not actually based off the movie, but off the end of the first series. Understandable mistake though as the series often repeats imagery and I had honestly forgotten about that part in the R movie (I just watched the first season over again but I haven't watched the R movie in a while.) Thank you so much! <3
The R movie? Oh yeah, Sailor Moon often repeated imagery. Being caught in vines happened more then once, Hotaru even has a vision of Eternal Sailor Moon in vines. The inspiration I took was directly from episode 45 though (mainly how Venus was posed, and expanded on that.)