Undead Siege is an alliance defense trial. Members first gather clues through Falcon Quests, then R4 or R5 schedules the launch. Once it starts, the Death Prison appears on the world map, sending out 20 waves of enemies.
Preparation
Before it starts, place your strongest suitable squad in the territory’s garrison. This can be done through your territory on the world map or through the wall fortification settings. The fight itself mostly runs automatically: the outcome depends on the defense chosen in advance.
If you’re not strong enough alone, ask allies to send reinforcements before it starts. R4/R5 should pick the difficulty based on what most active members can handle, not just the strongest players.
Rewards
The personal reward depends on how many waves your territory survives. The alliance’s shared reward accounts for members’ combined result. The maximum goal for a single run is surviving all 20 waves.
What’s still being verified
Exact requirements for each difficulty, the break between runs, and the reward lineup may vary. Before scheduling the event, R4/R5 need to check them directly in-game. The clue-gathering order, garrison setup, and wave count were confirmed against the Undead Siege guide on lastasylumguides.com.