Star Trek: The Next Generation had many iconic villains throughout its run, though few were as memorable as Data’s “brother” Lore.
In fact, Lore was originally envisioned to be an almost entirely different character, according to author and avid fan Larry Nemecek.
The misguided Synth created before Data by Dr. Noonian Soong gave Data, Picard, and the rest of the crew plenty of trouble throughout the series, but apparently, that wasn’t originally the intention for the character.