Collaboration Stages · Stage 2
Impregnable Fortress
不落の移動要塞
Impregnable Fortress is a Battle Cats stage in Street Fighter (Hard). It costs 160 energy and sends 7 enemy spawn lines — led by Guile (Enemy) as the boss — against a 200,000 HP enemy base, and clearing it rewards 22,560 XP. Its enemies carry the Floating trait, so cats that target it do the most work here.
Data updated: 2026-08-31
160Energy Cost
22,560XP Reward
200,000Enemy Base HP
4,400Stage Length
40Max Enemies
6.1Difficulty
Enemy spawns (7)
| Enemy | Strength | Count | First Spawn | Respawn | Base HP Trigger | Notes |
|---|---|---|---|---|---|---|
 Mooth | 800% | 1 | 6.7s | — | 100% | — |
 Owlbrow | 200% | 3 | 6.7s | 13.3s~20s | 100% | — |
| Owlbrow | 200% | ∞ | 0s | 30s~40s | 99% | — |
| Owlbrow | 200% | 3 | 0s | 20s | 99% | — |
 Blanka (Enemy) | 90% | 1 | 0s | — | 99% | — |
 Guile (Enemy) | 90% | 1 | 0s | — | 99% | Boss |
 Ms. Sign | 100% | ∞ | 900s | 900s | 100% | — |