Kuudra

Kuudra is a Boss fought in. Kuudra Keys are used to open chests from the Kuudra fight.

The Kuudra fight only allows 2-4 players at a time, similarly to Dungeons. However, you gain much more Crimson Essence from paid chests as opposed to dungeon essences, and much less Crimson Essence from free chests as opposed to dungeon essences.

Tiers
Multiple Tiers of Kuudra can be fought, with each having different requirements and costs. Higher tiers increase the difficulty of the fight, but give better loot.

Lore
Overgrown lava Kraken. The more sulphur it consumes the stronger it becomes.

Collection
Killing all the Kuudra Tiers increases the Kuudra collection. Each Tier gives an amount of points/kills towards the collection, see how much below.

Boss Fight
After starting the Kuudra boss fight, the bridge to the center collapses alongside Elle's supplies. Players must bring the supplies back into the center using a Starter Lava Rod, Magma Rod, Inferno Rod or Hellfire Rod. If one doesn't have any, they can buy Elle's Fishing Rod from the shop for 10 tokens. Once a supply pile's hooked all the way towards your direction, they must click it to pick it up. Tentacles and mobs in the arena can stop the players who are picking up the supply pile, with the former one attempts to pull them away, and the latter one attempts to knock the players away. However, when not moving and not facing the Tentacles, they won't pull the players away. Moving players must sneak whilst clicking the building materials gathered from supply piles to build the Ballista. Mobs and Kuudra Tentacles reduce the Ballista's building progress but once it's finished, it cannot be destroyed. The fight then proceeds to the next phase:

Players must then retrieve fuel cells for the Ballista. these are gathered the same away as Supply Piles at the start of the match. Once it's fully fueled, the Ballista can be fired. Kuudra can only be fired on if it's not submerged.

Basic Tier
In the Basic Tier of Kuudra, the fight was completed after defeating all 4 Tentacles. Now, players must bring supply chests to the middle, build the Ballista and fuel the Ballista in order to damage Kuudra.

Hot Tier
Same as Basic Tier but mobs have higher HP and deal more damage.

Burning Tier
Kuudra must be stunned to be damaged. To do that, players need to either use a Human Cannonball to fire themselves into Kuudra's Belly, or wait for the tentacles to eat them at the red blocks in front of Kuudra. Breaking a glass pod to 0% would stun Kuudra, allowing the team to damage it. Other parts of the fight are the same as Basic Tier.

Fiery Tier
The fight is the same as the Burning Tier.

Infernal Tier
Mobs spawn very frequently and are very strong during this fight. At wave 20 or higher, more than 25 Dropships can spawn one after one in 1 second sessions.

Infernal tier additionally adds a final phase where all players are teleported to Kuudra's Lair where he will respawn. Players can damage Kuudra directly on this phase.

Reward Chests
If every player fighting Kuudra dies, the fight will end, and the players will get access to the Free Reward Chest. If Kuudra is defeated, the players will be able to access the Paid Reward Chest, requiring the Kuudra Key for the Tier of the boss fight to open. Equipment variants from Reward Chests are dependent on the boss fight tier. The level of Enchanted Books from Reward Chests is dependent on the Tier of the boss fight. Level I Enchanted Books can be obtained from the Basic Tier, Level II from the Hot Tier, Level III from the Burning Tier, Level IV from the Fiery Tier, and Level V from the Infernal Tier.

The free chest contains an Enchanted Book if the fight was completed, and an Attribute Shard if the fight was  completed.

Trivia

 * Kuudra's main body is actually stacked two Magma Cubes.
 * Kuudra is the final Factions Questline, so after defeating it, the Questline has come to an end.
 * Kuudra is bugged and was able to be insta-killed with an Axe of the Shredded and a lot of . Now, players can use the same setup with a Voodoo Doll instead, and also when Kuudra is vulnerable.