The Lich of the original Final Fantasy doesn't have much screen time, but he doesn't need it. Throughout the early game, the player sees how the world has been wrecked by the four fiends. The first two largely destroyed civilization in the northern hemisphere, so seeing the effects of the Lich across the land is troubling. He remains shrouded in mystery, as players going into his deadly Cavern for the first time will only find his minion, a vampire miniboss. After a sidequest necessary to reach the Lich, you have to brave the toughest dungeon yet before finally meeting the guy. He turns out to be by far the hardest boss yet, with an arsenal of level 3 and 4 spells at his command along with tough paralyzing blows.

He is the death of the world in progress. Stopping him seems impossible. And even reaching him is a trial. So yeah. He leaves an impact.