Things you need to know: You will need two casters that can spam Remove Greater Curse non-stop. Using only 1 seems to not have time to cast enough RGC's to finish the event (more on this later.) You will need a toon who's PRIORITY purpose is to watch for 3 emotes and click the gumdrop trees on either side of the king in the proper fashion. And you will need someone with an aggro spell (can be the person who originally tanked the king) to kite the mummies at the end of the event.
The event starts by the tank engaging the king (rooted NPC) and spinning him so he's facing away from the raid (towards the wall that was originally behind him) This is the orientation in which his emotes during the raid will be, well, oriented by (from his left, right, etc.) Have the toon who has been delegated clicking duty already standing at this left gumdrop tree at the start of the fight. At about 89% he will emote that he glares to his left side, at that point, that left gumdrop tree will need to be clicked within at the most 1.5-2 seconds. If not, he will spawn two bears which can make tanking more difficult. After that power fades by properly clicking that tree, have that player run to the one on his right side. He will emote again about at 65%ish? (forget what %, just have that player looking very carefully), in which he will glare to his right. Again, click the tree. If the tree isn't clicked, the king's DPS will ramp up significantly. Again, have this toon run to the left tree, again, and prepare for the last emote, which will occur around 50% (I forget what occurs when this is not clicked, I think it may be another dps boost, or it may be more adds...). At this point, just full DPS burn the king. He will go completely invulnerable at 34%, so you may want to pull all DPS classes quite a ways away. Have your tank standing between your healers and the king, and have those healers spam RGC on the king non-stop. Every 3-4 or so casts, a mummy will spawn that will initially run to the closest PC, but use your tank to cast an AGGRO spell on it (they are invuln to damage, but aggro spells work great) and kite it around until the next one spawns. After the tank aggros the mummy, it moves quite slow (though they seem to move slightly faster the higher the tier event, or maybe thats just me.) You will need to cast RGC quite a deal of times, and you will get 5, maybe more mummies in that time period, that will need to be kited. But once enough RGCs are casted, the king is cured, depops, and you get your chest which you can /open for your phat lewtz
NOTE: His emotes are under the "Other" chat filter, and are yellow (assuming you haven't changed it).
On a side note, there is a semi-rare bracer that drops from trash in SSra that has a remove greater curse clicky on it, but I haven't tested this route yet. If you don't have the toons who can cast RGC naturally, you may want to test this and see.
Best of luck on your adventure, merry christmas, and thank you all to those who helped me with the information because there's no way in heck I woulda figured it out!
I just had a ranger doing the clicks who could DPS from range, so didn't matter much 
As for the first two tiers only requiring one RGC caster, I must be unlucky