Cons:
Enemies die too quickly. Content is too short. Majority of time spent is waiting for it to spawn.
Players that open up with aoes seem to get the most credit on the first wave.
Dominion Invasions are always the same.
Teleport between each of the 3 zones is annoying.
Increased currency for players that deal finishing blow. Causes players to hold out damage so they can get the finishing blow when its around 10%.
Dragon doesn't seem to move.
Suggestion:
Would suggest just adding a battlefield large enough for 50-70 of player can enter. Like a instance. Just have the player gain rewards the further amount of waves they defeat. Then just kick them outta the area after 20mins/end of the 8th/9th wave. Scale the item level of every wave from 119->135+. Basically a besieged without the npcs or mirror. Just spawn after spawn of enemy waves.
Then simply all the players inside get the same currency reward after every wave.
Entry on the 30min marker. 1 hour cool down for reentry. 80 Dominion points daily cap and get 10 points/106~212 beads for every wave tier cleared. Roughly 8/9 waves. 25+ enemy waves. Bead amounts in order of wave rewards, 106-106-106-106-106-106-106-212-212. Total: Wave4: 424, Wave8: 954, Wave9: 1166 beads. 20% chance of the 9th wave/mega boss appearing if 8th wave is cleared before the 15min mark. If 15min goal isn't melt and 9th wave doesn't appear the event will end on the 8th wave.
Waves 5+ won't spawn unless wave 4 is defeated within 6mins. Dominion Invasion will end if at wave 4 if the clear time is not met. This will prevent hard waves from appearing if overall dps isn't met and ending content early.