Server Time: 2pm daily
Location: Thueringen Lakeside (E5), Reboldeaux Queen's Gate (F9/G9)
Squad Size: 1-10 families
Duration: 30 minutes
This is a daily event mission (since v3.2 to v5.0) that can be completed solo easily and quickly. The main problem may be being active at 2pm (server time). If you can be around at that time, just do a quick run for free Enchantment Chips and maybe some other loot. This mission will be revised in a future update. See Revised Joaquin Barrier (Siege) for details.
Note that there is another event mission called Joaquin Barrier (Defense) which occurs at 2am daily and is considerably harder to solo due to the massive amount of mobs spawning to destroy your colonies. In Sword 2 (v5.0), the server notice for Joaquin Barrier (Defense) erroneously say that it is Joaquin Barrier (Siege) instead. You can tell them apart by looking at the in-game clock - one is in the morning, the other is in the afternoon.
For Lv.3 mission (channel 1), the mobs consist of L112-115 Undead/Golem from Prison de Joaquin. The mini-bosses include Jabberwock Captain (L112 Undead) and Dragon Head (L112 Golem).
First, destroy the 4 Enemy's Homes (L117 Other, 1053 HP) indicated in the map above. Like all colonies, they have very high DEF, so use fast attackers like Musketeers (Outrage Shot) if possible. Once this is done, there will be a zone notice saying, "The boss monster has appeared in the center. An enemy home has appeared in the center." Gullfaxi (L117 Undead) will then appear in the middle over the last Enemy's Home (L100 Other, 1900 HP), surrounded by several Fire/Ice/Lightning/Siege-Cannon Turrets (L15 Other).
Gullfaxi is non-aggressive, and will not attack unless attacked. The turrets can inflict status debuff like [Shock], [Burn], and [Freeze]. Destroy the turrets first, if necessary. Kill Gullfaxi for loot, then destroy the last Enemy's Home to complete the mission. Upon mission completion, all families will be moved to the start point, where 10 Treasure Chests await opening (1 per family).
Gullfaxi can drop Symbol of Capricorn, Le Noir, L84 Elite Equipment, L92-100 Enchantment Chips, and Pure Gold Bar. The other monsters drop loot like their non-mission counterparts, including Shiny Crystal and Mega Talt. The treasure chests drop loot similar to all other event missions (e.g. Team Arena, Infiltration), including EXP Cards, Skill Ring, Enchantment Chip, L100/L84E Equipment, and Event Cash Shop Consumables (e.g. Boost Potion, Teleport Scroll).