Illusion dungeon MVPs should follow the same spawn patterns as normal MVPs. They should spawn on the map randomly instead of fixed on wherever the last "trigger monster" was killed.
This comes after a bit of "drama" in global yesterday regarding a player found to be mobbing the Illusion Moonlight Dungeon's Nine Tails in order to spawn the MVP on them. The mobs that were being amassed were killed by another player and.. drama ensued.
After thinking about it for a bit, I really think this could have been prevented by having the MVPs spawn randomly on the map. It would prevent hoarding of "trigger mobs" and allow fair play to get to the MVP. In my mind, it's the same reasoning that was used in the decision to have field MVPs like Moonlight, Amon Ra, or other normally fixed spawn MVPs now randomly spawn.