This event is usually held on a monthly basis but lasts less than a week.
The Steel Castle Melfikya is a special event where players can upgrade their equipment with special boosts. Players can add to any piece of equipment they desire an additional passive ability like ATK +5%, MAG +10%, etc. thus allowing a player to make their equipment stronger.
Players progress through a 10 floor dungeon that requires Orbs to navigate (very similar to Raid Events). Unlike Raid events, however, the event provides a maximum of 10 Orbs at a time and they are separate from that of Raid events. The piece of equipment selected for boosting is removed from across all of the player's inventory and party setups (main party, arena, and so forth), so they should be careful not to choose an item the player is currently equipping so as to not weaken themselves.
On each floor player face waves of monsters at random, which usually fluctuate between no more than 1 or 2 waves of enemies per floor and usually only 1 Boss enemy on the later levels. Once the player defeats the enemies they will be given a choice between 3 abilities at random (they can repeat themselves) and the player must choose between one of them. An equipment can hold only a maximum of three added abilities this way and once they are filled, upon receiving a new one the player can choose whether to keep the abilities or exchange one for another.
The are certain limitations to be considered: For starters the event only allows a limit kind of equipment to be enhanced per event batch, for example one opening of the event may only allow Dagger, Guns, Katanas, Spears while another may hold Sword, Greatswords, Hammer, Whips, and so forth. Secondly an equipment cannot hold two of the exact same boost (i.e. it cannot hold two of ATK +15% at once), they can however stack on multiple ATK boosts like one ATK +10% and one ATK +15%. Thirdly, the boosts the player gets per floor are generated at random and do not majorly discriminate between Weapon type, as such one may end up with a seemingly ridiculous ability choice like a MAG boost for a Greatsword or an ATK boost for a Rod or Staff.
Despite these setbacks there is something to be gained: each kind of weapon has a chance at earning a special "Rare Ability" which in unique for each weapon type, namely Swords have a Rare Ability of their own, Greatswords have another unique to them and so forth. Obtaining these Rare Abilities is no easy feat as they have a very low chance of spawning, although the chance do improve the further into the dungeon the player goes.
A player can choose to retire from the event at any time, but upon doing so their exploration ends there with whatever abilities the player added up until that point, if they choose the redo the event they have to do it from scratch. If the player is at some point defeated the same happens.
Even if the player has an equipment with boosts, they can redo the event with this exact piece of equipment, doing so will treat the weapon as starting from zero and start filling abilities as if none were placed to begin with. Upon completing their expedition the player will be given a choice between the old set of abilities and the new one.
As a final consideration an equipment that has been boosted takes a separate slot than that of the standard equipment, that is to say a Excalibur with ATK +15% will be treated differently from a normal Excalibur, so the player should do well to make they have sufficient equipment slots as boosting too many of them may cause inventory space to fill up quickly.
Apart from the equipment boosts the player can earn a handful of rewards. Similarly to Raid events the player earns a score (but no event coins) when beating the floors. Upon earning a certain amount of score the player is given a reward for that specific threshold, which can hold Trust Moogles, Rare Summon Tickets, minerals or event special Potions that allow the player to refill Orbs.