Sky Fortress Invasion is a large endgame instance where a supernatural fortress has appeared over Prontera and monsters are pouring out of it into the city below. Scientist Doyeon has found a way to warp inside. You fight through two map layers of the fortress, collect five magical keys guarded by Key Keepers, unlock the fortress core, and defeat the four-headed wolf boss Stefan Jack Earnest Wolf.
💡This is a 3rd/4th-class endgame instance. You need Base Level 145 to enter. The entry NPC is Scientist Doyeon in the Prontera field north of the capital. Completing the Sky Fortress quest (quest 9418) is required before you can enter as a non-leader.
Requirements
| What | Details |
|---|---|
| Base Level | 145 minimum |
| Party | Must be in a party; party leader creates the instance |
| Pre-quest | Talk to Scientist Doyeon to start quest 9418; first-time entrance gives Sky Fortress Ticket (item 14505) |
| Cooldown | 23 hours (quest 9419 tracks the playtime gate) |
Talk to Scientist Doyeon in Prontera Field to start the quest.
Doyeon is a scientist who has been studying the fortress. Han and Doek, two soldiers, stand guard nearby. Talk to Doyeon as party leader to set quest 9418 and receive a Sky Fortress Ticket (rental item, 60-minute timer). You must use this ticket before it expires to enter.
After receiving the ticket, Doyeon opens the warp to the Sky Fortress entrance area.
Fortress floor 1: fight through the Golem guards and find the Key Keepers.
Inside the first map (1@sthb), you fight through large Golem-type guards blocking the fortress corridors. The first event involves a mini-boss Stefan form in the initial room before the key hunt begins.
| Enemy (mini-boss) | Level | Notes |
|---|---|---|
| Stefan.J.E.Wolf | 160 | Mini-boss form; 20M HP; appears at the entry room as a gatekeeper |
After the gatekeeper event, the key hunt begins. Eight Sky Fortress Key Keepers are hidden across the fortress. Each one must be killed to drop a piece of the core key.
| Enemy | Level | Notes |
|---|---|---|
| Sky Fortress Key Keeper | 160 | Eight total; scattered across both floors; kill all eight to unlock the fortress core |
Key Keepers spawn at fixed locations. Explore the full fortress map to find all eight.
Collect all five key fragments and unlock the core.
Each Key Keeper drops a key fragment. After collecting all five (the number of fragments per kill varies), the party leader can interact with the core lock mechanism to open the path to the final boss floor.
âš ï¸You need the Sky Fortress Ticket active to enter and to interact with the lock mechanism. If the ticket expires mid-run you cannot proceed further until you get another ticket from Doyeon.Final boss floor: fight Stefan Jack Earnest Wolf.
The final boss map (1@sthd) has the true form of the four-headed wolf boss.
| Boss | Level | Notes |
|---|---|---|
| Stefan.J.E.Wolf | 160 | 20 million HP; four different attack patterns cycling by phase (Wolf/Stefan/Jack/Earnest heads); each head change triggers new skills |
Each of the four wolf heads has different dangerous skills. Watch the boss dialogue -- the head speaking indicates which attack pattern is active. Move away from AoE telegraphs when the head changes.
Collect your reward from the Gold Treasure chest.
After the boss dies, a Sky Fortress Gold Treasure chest spawns. Open it to receive a Mystical Card Album.
Mystical Card Album -- opens to give one random card from any monster in the gameStandard drops from all Key Keepers and Golem guards throughout the fortressNotes
- Ticket is required. The Sky Fortress Ticket is a rental item with a 60-minute timer. If it expires you cannot interact with the lock or enter further. Get back to Doyeon before it expires if you need a new one.
- Level 145 hard gate. Below 145 Doyeon will not talk to you at all.
- 23-hour cooldown. Quest 9419 tracks the playtime gate.
- Mystical Card Album is the jackpot. The album gives one random card from the entire game card pool. High variance but a high-value reward.
- Key Keepers are spread out. Map exploration is required. Do not skip any part of the fortress or you will miss Key Keepers and block the lock step.