Dragon Invasion

Dragon Invasion is a recurring event that takes place every Monday and Thursday from 12:00 until 21:00 server time.
Each player is allowed to challenge the dragon 3 times per day. Players will be ranked according to the total damage dealt to the dragon during the invasion.
=Azure Dragon King= 
On the continental Erathia, people are frightful to think of Azure Dragon. Such foulest dread creatures perches on an untrod and frozen cliff. Legend says that its breath is able to freeze the toughest steel and its roar will make the highest peak collapse. The dragon is even gifted to control the thunder......But no living beings have ever seen it.
==Skills==
Skill 	Description
Nemesis 	When attacking, the Azure Dragon King causes damage to all units within a certain area. If a unit is downed, the Azure Dragon King will release a thunderbolt that randomly kills another unit
Frost Breath 	When the Azure Dragon King attacks, it has a 15% chance of triggering Dragon Breath, causing damage to units within a large area in front of it, and decreasing their healing for 10s
Dragon Skin 	When hit by a Crit Hit, the Azure Dragon King will increase its own unit's damage. The effect can be stacked and it has a chance to form a snowstorm
Dragon's Will 	The Azure Dragon King summons a young dragon every 30s. The young dragon will cast Enduring Defense every 30s that increases unit's damage reduction and dodge for Azure Dragon units and itself over the next 180s
Snowstorm 	The Azure Dragon King forms a snowstorm every 45s, causing tons of damage to all hostile units and silences them for 10s
Forbidden Scale	The Azure Dragon King is immune to all percentile damage caused by hero skills. The Azure Dragon King is immune to all percentile damage caused by unit skills. (The unit skill will deal damage based on Unit ATK*10.) The Azure Dragon King is immune to all crowd control skills. The Azure Dragon King is immune to percentile damage caused by machines. The Azure Dragon King's DEF Reduction Resistance is greatly increased.
=Strategy=
On the current version (24.11.2020), here is an overview of some recommended strategies. (feel free to experiment on your own and find a better one)
==Early game==
The meta before level 80 is a bit more complicated and players have reported various heroes working. Specific hotspot heroes can make a difference. While Gelu would be an obvious choice, reports of Crag Hack or Solmyr for example giving good results have also emerged.
Tazar seems to be the winner of this, with Death Match dealing spontaneous bursts of high damage. It's also very random so it can be a tedious process - requiring the player to repeat attempts many times to get the best score. But buying Tazar only for Dragon Invasion is not recommended. 
==Late Game==
After level 80 the meta tends to stabilize around Gelu and the two archer units, Marksman and Wood Elf.
The entire strategy relies on grouping the two, then boosting them to their maximum potential. This strategy actually leads to most of the damage being dealt in the first 30s of the battle.
===Spells===
First of all, Gelu's spells are one of the primary boost options for your archers. Keeping them grouped allows periodic buffing with Precision and Slayer for high bursts of damage. Spell Mark is also very important, with both Slayer (more accessible) and Rush Tactic (more expensive) giving good results.
===Artifacts===
Since Gelu does not rely on spell damage, at this point Titan's Thunder is your best bet at dealing additional damage to the dragon periodically. Other options are not that important - just use the best artifacts that you have.
===Units===
Here is one of the current top formations in Dragon Invasion after level 93 (with full awakenings):
The idea for your unit selection goes in two directions:
* You can further buff and protect your archers - which the Genie can do very well as long as the red and green buffs land on your archers. She will also heal your units thanks to Gelu's Stone Skin not very useful anywhere else.
* You can debilitate the dragon by decreasing its damage reduction. All the remaining units you see on the list have one way or another for doing that. If you lack the SR+ units or do not own the relevant damage reduction awakening skills (Dendroid Soldier requires the third awakening ability for example), you can always find substitutes like Unicorn or Walking Dead.
Remember that only the archers are meant to be damage dealers - everything else is there to support them in this direction, not deal actual damage.
===Emblems===
Emblems are essential to make the strategy work.
* Path of an Assassin on your archers - by far the most significant emblems in the strategy. This further plays into "initial burst damage" theme and fantastically boosts your damage output. Orange is preferable but purple also works great.
* Darkness Enlightenment on Manticore (or one other 4x unit with the best ATK speed) - further increases damage reduction. There is no point in putting it on more than one unit - you can't achieve more than 25 stacks anyway and outside DI you will find little usage for it. Purple work perfectly fine too.
* Everlasting Secret or Anger on support units - relevant if the "decreases damage reduction" scale with your skills. Anger is better if the scaling is on the ultimate. Of course orange are preferable. If a unit could benefit from either of the two, prioritize this to Darkness Enlightenment (but make sure you have that on exactly one unit in your formation!)
If a unit does not fit into any of the three categories (e.g.: Dendroid Soldier, Nightmare) above, you can put whatever emblems you want on them.
= Rewards=
Players will receive rewards for participation as well as extra rewards depending on the player's rank on the leaderboard at the end of the invasion. In addition, every member of a Guild will receive rewards according to their Guild's position on the Guild leaderboard.
Rewards unique to Dragon Invasion come in the form of 
Star Sigil, Rare Dragon Chests and Legendary Dragon Chests.
Dragon Chests may contain skill gems, experience potions, gold, Ancient Temple Scroll, Astro Silver or Diamonds.
Individual Leaderboard Result Reward
Rank 	 	Rare Chest	Legendary Chest
1 	660	20 	10
2 	645	18 	8
3 	630	16 	8
4 	615	15 	6
5 	600	14 	6
6 	580	13 	6
7 	560	12 	6
8 	540	11 	6
9 	520	10 	6
10 	500	10 	6
11-20 	460	8 	4
21-30 	420	7 	4
31-50 	370	6 	4
51-100 	320	5 	4
101-200 	260	4 	2
201-500 	240	3 	2
501-1000 	220	3 	2
1001-2000 	200	2 	1
2001-5000 	200	2 	1
5001-10000	200	1 	
Guild Leaderboard Result Reward
Rank 	 	Rare Chest	Legendary Chest
1 	1000	9 	3
2 	950 	8 	2
3 	900 	7 	1
4 	850 	6 	
5 	850 	6 	
6 	800 	5 	
7 	750 	5 	
8 	700 	5 	
9 	650 	5 	
10 	600 	4 	
11-50 	550 	3 	
51-100 	500 	3 	
101-1000	250 	1