Ideas for roles. I am just tossing these out, so they may or may not be good:
Goblin Kidnapper - has a night ability to kidnap someone. If they target the Child, both the Child and the Kidnapper are removed from the game and the Kidnapper wins. If they target someone else, they die and lose the game. If for any reason they are unable or unwilling to kidnap the Child, their goal becomes to survive.
Kobold Thief - At the beginning of the game, two players are given special abilities: one player (who is guaranteed dwarf) is an Artifact Creator, in addition to whatever role they already possess. Another player is an Artifact Holder, in addition to whatever role they already possess. The Kobold Thief can investigate one person per night to determine if they are an Artifact Holder. They may also instead attempt to steal the artifact from the Artifact Holder. If they attempt to steal from the wrong person, they die and lose the game. If they successfully steal the artifact, the Artifact Creator dies and the Thief wins the game. If the Artifact Holder dies, a new Artifact Holder is chosen from the remaining players (excluding the Thief, obviously). The Artifact itself should be awesome or humorous in some way.
Deep-Cover Elf: This Elf has a dwarf power role (like Duke or Sheriff). In addition, the Deep-Cover Elf can also act as a Role Cop, possibly allowing them to have multiple night actions. However, the other Elves do not know who the Deep-Cover Elf is, and the Deep-Cover Elf does not know who the other elves are.