Besides the world bosses, there are many other daily/weekly quests that involve killing solo scroll bosses. These are acquired from your Black Spirit, a rare drop from monsters, by combining items in your inventory, or by purchasing additional scrolls from the Pearl Store (F3) under the Loyalty Tab.
There are also Guild scroll bosses which require either a small party of 5 people, or a larger party of 20. These bosses can drop the Liverto weapon, which is one of the best weapons in the game.
I highly recommend joining the boss hunting discord servers. These servers announce when bosses spawn and keep you up-to-date with live HP percentages.
World bosses drop legendary, yellow grade weapons, which are currently the best weapons in the game. Only a few lucky players will receive a chest from the boss after it’s been killed. Opening the chest will give you the weapon for the class you open it with. You can transfer the chest across characters, using your warehouse. All world bosses spawn with a 8-12 hour timer (randomly) from the time they were killed. Each channel has a different timer.
Kzarka spawns inside the Serendia Temple which is located south of Heidel city. This boss drops legendary, yellow grade primary weapons, known as the Kzarka weapon. The weapon has 18-22 AP with +3 attack/casting speed and 2 sockets at +0. It is the BIS weapon. Enchanting will increase damage and accuracy.
Ancient Kutum spawns in Valencia. This boss drops legendary, yellow grade secondary weapons. The weapon has 4-6 damage, 4 defense, Ignore All Resistance +10% and 2 sockets at +0. Enchanting will increase damage, defense and accuracy. The weapon is one of the two choices for secondary weapons and can suit some classes better.
Nouver spawns in the Valencia Desert at 1 of 3 different locations (randomly). The coordinates for these locations are: x8100y2300, x7300y50 and x10050y350 (locations shown on the map below are not 100% accurate). The dragon will spawn 30 minutes after the spawn announcement has been made. Just before Nouver spawns, the location will become dark. This boss drops legendary, yellow grade secondary weapons. The weapon is BIS for most classes and has 6-8 damage, 10% damage reduction and 2 sockets at +0. Enchanting will increase damage and accuracy.
Karan (HARPY QUEEN)
Karan spawns at the Karanda Ridge which is located north-east of Calpheon city and south-west of Velia Town. This boss drops legendary, yellow grade awakening weapons, which require level 56+ to use, as well as completing a quest to unlock the skill tree. The box is called the Dandelion box and is BIS for all classes.
Red Nose drops yellow grade armor chest piece along with various other items, such as liverto bundles and crystal gems. The boss armor piece is not the BIS but it is still worth killing the boss.
Dim Tree Spirit
Dim Tree Spirit also drops a yellow grade armor chest piece along with various other items, such as liverto bundles and crystal gems. The boss armor piece is the BIS with high defense.
Dastard Bheg drops a yellow grade armor gloves piece along with various other items, such as liverto bundles and crystal gems. The boss armor piece is the BIS with high defense and accuracy.
Giant Mudster drops various items, such as liverto bundles and crystal gems. It is still worth doing the boss for these items.
Two non-instanced dungeons were added to Korea in December 2015. They were called “Ahkeuman Ruins” and “Historic Ruins”. Both dungeons are located underground and can only be entered by going through a portal. The portal will randomly spawn somewhere in the Valencia desert.
Below are some example videos of combat and exploration:
Some of the monsters found in the dungeon are very powerful lava monsters, which can also be found near the Sulfur Mines in the Valencia Prison. The dungeons are designed for a small party all level 56+. It is solo-able at level 56 but even with good gear it isn’t viable. The monsters will be purple or red, take a long time to kill and hit very hard. However, they do drop quite rare/unique items, and is a great place to hunt in a party or guild.