This is a recruiting event. One is randomly selected into King or Joker faction.
In a King faction, we can obtain King's crown to add certain points into our event points. We can only perform conversions onto Swordsmen, Paladins and Arcane mages.
These are the materials that can be used to convert thise units. There are actually 3 types of debris but I do not have the image of the 3rd one and I do not recall its name. I used to own lots of it but I do not recall how did I did I manage to collect so much. Perhaps I won them from the wishing well or Demon invasion or other events. The Debris of illusion can be collected from dungeon attacks. The Debris of light can be exchanged from your Alliance vault.
To obtain the crown, simply click on any of the above materials and use AT LEAST 2000 of them. You will be granted an extra 200 new somdier types and the crown as stated in the system mail.
To use the crown, just click it from the Item chest. One crown gives 0.02 points from the recruitment that finishes the earliest and it willbe notified via system mail. The point is then added to your event score. Not much it seems but if you are recruting soldier types with bigger scores like the Wooden puppet, the Golden scorpions and those Sky City soldiers, the points is of course better.
Good luck kings!