Mount Pillar Lich

The Mount Pillar Lich was a lich who opposed Swayne. He turned it into a Grisgol and forced it to guard the spirit shackle at the centre of Mount Pillar.
This being was a human native to a village in the Shadowfel which had been conquered and enslaved by the Drow empire and human collaborators. They attacked the abusive guard, Ralph, and fled. Later, after having gained necromantic powers, they liberated their village at the cost of an arm, which they replaced with a necromantic bone arm graft. The townsfolk feared them and viewed them as another monster. After being rejected by the villagers, they encountered Ralph a second time and easily dispatched him, saying "mercy has limits". They then reanimated Ralph as a skeleton.
They later became a lich, using the key with which they had freed themself from their shackles as their phylactory. Said key was tossed into the bowls of a Shadowfel sea monster.
Later, in revenge for Swayne killing off the survivors of the village, the lich attacked him with a powerful army of giants and undead. Swayne destroyed them effortlessly without the bored expression ever leaving his face. He then turned the lich into a Grisgol. At some point, a Mindhunter retrieved the key from the sea monster and Swayne now wears it around his neck.