OK, in total love! I adored Nei when she first showed up way back when, agonized when they killed her off, and LOVED her overall aesthetic. It's one I wish they'd kept as the setting went forward. Indeed, I wish the LORE had stayed consistent as things moved on.
Honestly, you should. The original Phantasy Star 2, where Nei appeared, was well-written, had some surprisingly deep lore, and played well. Some of the ideas carried forwards through the series, but not intact, sadly. This, though, is the origin, and I strongly recommend it.
you totally should! the classic series (apart from 3, skip that one) still holds up quite well, though definitely play 2 with dungeon maps handy. Phantasy Star 4 is still a top-tier 16-bit jrpg, standing shoulder-to-shoulder with Square's best from the era IMO, and one of my all-time favorites 💙