Those are the side quests:
[Elite] Y'hagra trophy
[Elite] Kha'rhun trophy
[Elite] Dor'lyn trophy
[Elite] Lt. Arbu'ekth Thophy

Each quest Player need to kill 20x time the boss named on it. The "problem" start when we can't take all quests at once, needing to be lucky to get the boss that the quest asks for, turning it much boring, repetitive and luck based.
It could be solved with either:
•The "go to" of the quest teleport the player for the map that boss is
-Example:Quest y'hagra>go to> teleported to the map that has y'hagra as a boss.
Or
•Make it possible to take the 4 bosses quests all at once, without the need of done one after one
Currently it works like:
Kill 20x Y'hagra, after it done, player get kha'hun quest.
Kill 20x kha'hun, after it, player get Dor'lyn quest.
Kill 20x Dor'lyn, after it, player get Lt. Arbu quest.
Kill 20x Lt. Arbu.
@asommers