Land of Mist Legendary Mine: Ouroboros

This is a new feature of Land of Mist following the defeat of monsters resulting from a HARD Explore

When exploring in Land of Mist you are now given two options - Normal explore and Hard explore. If you choose Hard explore you will be given between one and three monsters (combination of Cronus Astaroth, Vargulis, Samael, ??) to defeat.

Once the land has been cleared there is a normal 24hr collect period. At the end of the 24hr collect, the land will either convert to the normal 48hr protected mode OR generate a legendary mine monster (Ouroboros)

Ouroboros
You have 168 hours to complete the battle before he flees.

Basic Information
Ouroboros has 2.5 Billion health. Only guild members may participate in the battle. Of these participants, only a set number can participate based on that player's level at the time of joining the battle.
 * 100 people levels 500+
 * 40 people levels 150-499
 * 20 people levels 100-149

This battle uses the Monster Stance and Piercing/Resistance systems.

Piercing/Resistance
Ouroboros has Piercing Resistances, and Wind Weaknesses.
 * Main Body: -50 Wind Resistance, +100 Piercing Resistance

Monster Combat System
Ouroboros uses a similar monster combat system to the Astaroth/Vargulis/Samael) where players have the opportunity to gain bonuses by attacking all at once. When attacking, if a player's equipped Alliance Stance exceeds the monster's stance difficulty rating, the monster battle will receive points equal to the amount of stamina used.

Your equipped hero type determines the benefit type and the hero stance power is determined by the sum of the hero level and same type heroes in alliance with him.

Defensive alliances increase the critical stance bar which gives a flat percentage increase to the chance to get a critical hit. Offensive alliances increase the damage bar and the damage done by every attack. Balanced alliances reduce the rate at which the critical and damage bars decay. Damage added through these bars does not count towards the minimum threshold to receive rewards. A player's total damage towards loot can be observed as their Contribution total.

The Critical stance bar and Damage bar give static percentages once certain amounts are reached, as noted in the table below. When one level is filled, the next level starts from zero, and the corresponding bonus is activated for thirty minutes or until the current level goes below zero points. When the bonus expires, the bar starts from level zero. If the player's equipped stance is greater than the difficulty rating, the amount of stamina used is added to the corresponding bar. Ouroboros's stance difficulty rating is 30. * Levels 2-MAX not verified

Siege Weapons
While fighting Ouroboros, there are 5 siege weapons that can be launched to deal extra damage. ????

= Lore = On summoning - no text

Ouroboros Slain
The Desert Wastes are home to many monsters where they lurk and multiply unchecked by heroes. One such monster is Ouroboros, once an ordinary snake until it attacked an unfortunate wizard crossing the desert. The dying wizard cursed the serpent to an eternity of endless agony and the fell magics transformed the snake into the monster Ouroboros. Unable to die, the snake wandered the wastes devouring all it came across and slowly growing in size and power.

Over the centuries, its mind grew along with its body and it developed a intelect twisted by the constant pain. It learned to hate and despise wizards because of the curse and made a special point of hunting them whenever they ventured into the wastes. Eventually, travelers learned to avoid the wastes and the number of wizards venturing through them dwindled to nothing. Rumors grew of a unknown horror that lurked within the wastes and even the most stalwart travelers found alternate paths.

With no more wizards to devour, Ourobros has ventured out of the wastes seeking more wizards to vent its rage upon. Though you are tempted to let it eat some of the finger wagglers to teach the rest an important lesson about overly dramatic death curses, you feel like you should kill the overgrown snake before it starts eating everyone.

Gathering your allies, including a group of nervous wizards, you head out to stop the serpent's rampage. It is easy to follow the track of the serpent by the trail of destroyed mage towers and ruined academies. Eventually you come across the worm near an abandoned mine and lay a cunning trap. Ordering the protesting mages to the mine entrance, you hide the rest of your army nearby. It does't take long before Ouroboros take the bait and moves to the old mine.

As it moves to devour the mages, the rogues and warriors strike from the flank while your mages and clerics attempt to magically bind it in place. The battle appears to be going well until the magics holding the serpent at bay suddenly fail. It seems that it has acquired a resistance to magic after its years of devouring wizards. With no time to spare, you interpose yourself between the creature and the now panicking wizards. While it is focused on the tasty, panicking, treats behind you, you ram your sword straight into its belly dealing its deathblow.

With Ouroboros dead, the grateful wizards promise to enchant the abandoned mine to ensure a rich yield. You accept reasoning that at least this will keep them occupied and not making ill-conceived uncontrollable abominations or whatever it is that wizards do in their free time.

= Rewards =

Rewards While Fighting Ouroboros
108 Attack Essence

Loot Damage Threshold
The estimates here are derived from user contributions to the Ouroboros Loot Spreadsheet. You can help improve these estimates by adding your own loot reports to the spreadsheet.
 * The 99% thresholds are estimates based on what has been reported so far. No player or dev should ever guarantee you a drop of any quality for any damage to any monster.

Rares
Rare drops are based on activity (labeled "Damage").
 * 1 Rare Drop
 * starts: 11.4 million
 * 99%: 16.9 million
 * 2 Rare Drops
 * starts: 21.1 million
 * 99%: 47.9 million
 * 3 Rare Drops
 * starts: 62.2 million
 * 99%: 102.6 million
 * 4 Rare Drops
 * starts:143.1 million
 * 99%: Does not Exist

Epics
Epic drops are based on activity (labeled "Damage").
 * 1 Epic Drop
 * starts: 24.7 million
 * 99%: 34.3 million
 * 2 Epic Drops
 * starts: 50.5 million
 * 99%: 62.7 million
 * 3 Epic Drops
 * starts: 90.9 million
 * 99%: 111.0 million

Legendary
To be eligible for a legendary loot drop, you may need 78M Contribution Points.

If you have the required Contribution Points, the chance of a getting a legendary drop depends on your activity (labeled as "Damage").
 * 1 Legendary Drop
 * starts: 125.0 million
 * 99%: Does not Exist