This article gives an explanation of the Demonic Siege event that was introduced in update 4.9.0 in King of Avalon.
10/21/2018 - www.youtube.com - www.gamesguideinfo.com
Second attempt of Demonic Siege Event, reached until wave 29.
The Demonic Siege event can be activated by R4 or R5 in the Event Center. Each reset it can be activated 3 times. Once activated players can join via the Event Center. It is played in a special map, a bit like Merlin Trials, so location of your account is not important.
During the Event you need to protect the Portal in the middle from waves of Formorians. This can be done by occupying the 5 fortresses located around the portal.
There are waves of attacks of Formorians. During each wave each of the 5 fortresses will be attacked by Formorians. Any formorian that is not beaten by your defending troops will go on to deal damage to the Portal.
Once the Portal has 0% health remaining you have failed the event.
Each wave the formorians will get stronger.
There are a total of 30 waves, if after 30 waves your Portal still has some health remaining, you have won the Demonic Siege.
There are six difficulty levels, once you have beaten easy, you can next time try the next difficulty level.
You can plan in the Demonic Siege ahead of time, but this is purely a administrative feature, the demonic siege in the end still has to be activated.
For this event the combat boosts and March capacity are taken from the participating players, but the troops are provided by Merlin. I am not sure you need a free march to join, but I don't think so.
When a wave is announced you will see the number of Formorians in the wave above the troops, e.g. Remaining Formorians: 6.
Each player defending a fortress only defends against one Formorian each wave, so if you have less players than Formorians, there will always be some Formorians getting through to do damage to the portal, no matter how strong your defending troops are.
If a player is unable to beat a Formorian completely, the remaining part goes on to the next defender (in order of strength). The strongest player is the first who does battle and after that in order of diminishing strength.
During one wave you can move your troops between different fortresses, and this way they can attack different Formorians during one round.
There are different type of Formorians. They go from strong to weak and from slow to fast. Fortress 1 gets slow and strong Formorians, fortress 2 and 3 medium speed and strength, and fortress 4 and 5 get relatively weak and fast Formorians.
The amount of attacking formorians is also not the same for each fortress and even for the same fortress not the same each wave. As far as I have seen and recall fortress 1 always gets 2 formorians, fortress 2 always gets 4, fortress 3 gets 4 or 5, fortress 4 either 6 or 7 formorians and fortress 5 6, 7 or 8 formorians.
Most important thing is just to have a lot of accounts. They don't have to be very strong to reach far, my farm accounts have combat boosts of around 200% and they were able to beat waves in the fortresses 4 and 5 until the last waves. Even a lot of weaker accounts can be very useful.
It's good to monitor performance and learn how accounts perform. Ideally you have a number of accounts that you don't need to move that will perform well until the highest waves.
It is possible to move between fortresses during one wave. We are typically moving several accounts between fortress 1 and fortresses 4 and between fortress 1 and fortress 5 (I think these are the only possible moves within one wave). This allows you to still prevent damage if you don't have enough accounts.
It might be good to assign leaders for each fortress who make sure they have enough accounts in there, it will be difficult for one person to monitor and communicate on all fortresses. Especially at the later stage when it will be for example necessary to have 1 or 2 more accounts in a fortress than the attacking formorians.
So now and then Bonus Formorians appear on the map. I don't think there are fixed rounds and locations for that, but when they come there is an indicator at the left top. These need to be killed for bonus rewards. Everyone participating in the event gets the bonus rewards, so it is not important who kills them.
It might be best to make rules for who will kill the bonus formorians when they appear, e.g. an army in a nearby fort that does not move between fortresses. One of our runs 4 armies jumped on it (while the first one killed it) and some of them were not in time to reinforce a fortress causing us to take damage.
Initially all rewards were related to the Avalon Artifacts, but since update 5.1.0 that seems to have changed to be focused on Lord Gear. You get Dragon Essence, Steel, Basic Materials, and Rare Material Chest Fragments now. Also useful, but it does seem to become a lot more difficult to improve your Artifacts now.
The event seems to be quite original, and not really focussed on big spenders because having many accounts is very important as well, arguable more important than having strong accounts. That is the nice part, the not nice parts are that it is initially quite complicated and as always the in game documentations falls short. Besides that there are a huge amount of waves and once you have played this a few times it will get tedious: if you don't have enough strong accounts you need to be monitoring all the time and moving troops around. It will likely be more difficult to find enough players once players start to experience this as repetitive and tedious.