🏗 Helheim buildings
• Helheim Forge
• Helheim Shop
• Warrior's Hall
Levels: 1 → 11, 10 upgrades in total.
Each upgrade unlocks after clearing one floor at 3★ on every node.
Floors at 3★ → level
0 → 1
1 → 2
2 → 3
3 → 4
4 → 5
5 → 6
6 → 7
7 → 8
8 → 9
9 → 10
10 → 11
Per-level building stats are not entered yet.