World Monster

The World Monster (also called "The Cerberus") is a new kind of monster. A banner linking to it appears on everyone's Home page twice a day at specific times, every day, 15 minutes before you can start hitting it. It remains alive for 30 minutes, and you can collect up to 1 hour after its death.

The Word Monster is not a permanent feature. It is made available more or less arbitrarily for indefinite periods of time. 

Refine Crystals were introduced with the World Monster. You get them as a reward when you collect, but they also drop randomly when hitting it.

Using bigger stamina buttons gives more chance at a drop. Reports seem to indicate that using the 200 stamina button gives a Crystal almost every time.

The World Monster can't be failed. Whether he gets killed or not, at the end of the 30 minutes, it will be displayed as a victory with 0.00% Life Remaining. Everyone will be able to collect.

What matters to get the rewards isn't directly the amount of damage you dealt, but your rank among all attackers. Only the first attacker on the leaderboard will get Odin, all the others will get varying amounts of Refine Crystals.

In-game Information

Tips:
1. Event Time : 8:00 & 20:00 PST.
2. Collect rewards end: 9:30 & 21:30 PST.
3. Every player attacked the monster will gain rare items.
4. Please collect your rewards before they expire.
5. Damage doesn't count towards "Monster Leaderboard"
6. Equip your best loadouts and wreak havoc!

Rewards:
1         Refine Crystal ×50 & Odin ×1
3         Refine Crystal ×30
10       Refine Crystal ×20
50       Refine Crystal ×10
100     Refine Crystal ×5
1000   Refine Crystal ×2
1000+ Refine Crystal ×1

Details

• It appears the World Monster has 15B HP (source).
• Its breakpoint seems to be extremely low, probably 0 (source).
• It doesn't drop any Essence.

Availability 

      1. Oct. 23, 2017 - Nov 1, 2018 (375 days)

On Oct. 31, 2018, a News Headline was added in game:

World Monster Suspension Notice
 The World Monster event will be suspended indefinitely as of Nov 1st 2018. 
The brand new Team Battle feature is coming soon.

Shortly after it was removed, the World Monster was replaced by the Colosseum.

      2. May 13, 2019 - June 25, 2019 (44 days)

On May 8, 2019, another News Headline was added:

Countdown to Colosseum Season 1
Dear heroes, the first season of Colosseum will be officially over on May 13th 00:00 PDT,
and it will be suspended to prepare for a new season with new contents and rewards.
Please note that your Honor Points won't be cleared when next season starts.
During this time, the World Monster would make a comeback.
Enjoy an exciting season finale of Colosseum and get ready for the Cerberus next Monday at 8 am PDT!

The World Monster stopped appearing on the day the season 2 of Colosseum started, on June 26, 2019.

      3. Sept. 25, 2019 - January 6, 2020 (104 days)

The World Monster started appearing again the day after Colosseum Season 2 ended, and was suspended when Season 3 started. Related News piece: Notice - January 6, 2020.

Notes

• Introduced October 23, 2017 . 
• First discussion thread (forums)

Details

• The World Monster is the main way to acquire Refine Crystals. As stated on the Refine page in-game: "You can get Refine Crystals by fighting World Monster at 8:00 & 20:00 PST". The Refine feature was introduced January 9, 2018, about 10 weeks after the World Monster.
• Its HP is displayed in percentage at the bottom right of the monster.
• The only tabs available are "Attack log" and "Chat log", as there is no need for a "Status log", and the loot is displayed when clicking on the "question mark" button.

Strategy

• Getting in the top 1000 requires very little stamina (sometimes 1 stamina is enough). So you can get 2 Refine Crystals twice a day very easily as long as you show up for the battle and collect.
• Anyone can comment on the chat tab, and many use it to promote their army code.

History

• When the World Monster was first introduced, the best reward was already Odin, but the other rewards were Common Chaos Shards.
• Its HP has been adjusted. When it was first introduced, high level players were racing for the first place to get the best reward, so it would die within 2 minutes with several players dealing billions of damage, even though it had a huge amount of HP (30 billion? More?). After a while, its HP would never reach 0.00% so it was lowered (it has about 15 billion HP currently). However nowadays (September 2018) most of the time it doesn't even come close to dying before the battle time is over (it often has over 75% HP remaining).