Lupo is found mostly in secret alcoves throughout the world. You must buy a map of each area to satisfy this achievement.
1) Inkwater Marsh, 25 Spirit Light
2) Kwolok's Hollow, 50 Spirit Light
3) The Wellspring, 75 Spirit Light
4) Baur's Reach, 125 Spirit Light
5) Mouldwood Depths, 125 Spirit Light
6) Midnight Burrows, 125 Spirit Light
7) Luma Pools, 125 Spirit Light
8) Windswept Wastes, 150 Spirit Light
9) Willow's End, Free