It seems Knock Tortoise also live in Atlio City Ruins. They have bad tempers, so I doubt they get along well with other dimension monsters, but could you go check?
Quest Specifics
- Quest: Rumble in the Ruins
- Type: Slay Enemy Quest
- Rank: 8
- Objective: Defeat Knock Tortoise x 5
- Location: Atlio City Ruins
- Reward: Magical Elixir x 5 and 2,300 B