Siege Assault skill that can improve the attacking capability of engineering soldiers
| Level | Atk Bonus | Time | Wood | Stone | Metal | Gold | Requirement | Requirement |
| 1 | 1 | 09:26:26 | 140000 | 168000 | 112000 | 420000 | Armory 13 | Siege Vigor 5 |
| 2 | 2 | Armory 14 | Siege Vigor 6 | |||||
| 3 | 3 | Armory 15 | Siege Vigor 7 | |||||
| 4 | 4 | Armory 16 | Siege Vigor 8 | |||||
| 5 | 5.5 | Armory 17 | Siege Vigor 9 | |||||
| 6 | 7 | Armory 18 | Siege Vigor 10 | |||||
| 7 | 8.5 | Armory 19 | Siege Vigor 11 | |||||
| 8 | 10 | Armory 20 | Siege Vigor 12 | |||||
| 9 | 12 | Armory 20 | Siege Vigor 13 | |||||
| 10 | 14 | Armory 20 | Siege Vigor 14 | |||||
| 11 | 16 | Armory 20 | Siege Vigor 15 | |||||
| 12 | 18 | Armory 20 | Siege Vigor 16 | |||||
| 13 | 20.5 | Armory 20 | Siege Vigor 17 | |||||
| 14 | 23 | Armory 20 | Siege Vigor 18 | |||||
| 15 | 25.5 | Armory 20 | Siege Vigor 19 | |||||
| 16 | 28 | Armory 20 | Siege Vigor 20 | |||||
| 17 | 31 | Armory 20 | Siege Vigor 20 | |||||
| 18 | 34 | Armory 20 | Siege Vigor 20 | |||||
| 19 | 37 | Armory 20 | Siege Vigor 20 | |||||
| 20 | 40 | Armory 20 | Siege Vigor 20 |