It's a Troublesome Temple weekend buff!

Bigfat, abuse the "level all crusaders" button. Since which slot is lost each 25 levels is random, "strategy" is kind of thrown out the window. Just keep all your crusaders as leveled as possible and hope that whichever 5 crusaders you have left near the end gives you enough DPS to proceed until 450. If it was predetermined which slots get nuked, there would be more opportunity for strategic planning, but "Holy Grail" is very much just a "cross your fingers and hope for the best" objective. The most I can say is to favor gold finders because they'll benefit your levels for a little while even after they've been nuked.

thanks guys, I meanwhile figuered that too!
Well that sucks, but I have around 750k Idols, so lvl 450 should be reached no matter which crusader is left in the end.....

i easily got to 575 when the last person of 23 was no longer available. merci. ryan, everuone can be dps when they alone are leveled up a lot, but gold bonus sort of sucks so do even 10 minute gold missions, and only turn them in, or open silver chests by going back to area 1 and having your full formation.

I finally squeaked past after wrapping up some gold missions and taking advantage of the 4-hour DPS and gold buffs by watching sponsoring videos.

@Carlene -- You need to add Crusaders with the Tank tag. Polly will give each of them a bonus +50% to your DPS.

Tank Crusaders are listed here: http://crusaders-of-the-lost-idols.wikia.com/wiki/Category:Mission_Tag_Tank

I'm trying to earn Karma points -- I got help some more experienced players yesterday on the tier 2 "Holy Grail" mission. :)

Get used to that, bigfat. I've gone 12 deep without a jeweled chest, and I can never get a straight answer when I ask what the drop rate is.