Few days ago, our clan and some other peeps did one of the hardest raid on the server, now a misison based one with 23 people. It's in Viron, at the Clock Tower, we often do some of the lower floors, just to get some keys for higher floors, so now we decided to do it till the last room.
We easily handeled to go through the 1st and the 11th floor to get in the last floor, the Lost Hour to get face to face to the last boss, which can drop materials for Strata Weapons craft and other valuable stuffs and there's also a roulette, where we can rarely get Punisher stance book, crafted ELN and recipes for ELN, Devil weapons and Magic accesories.
Our strategy was based on dps and cancel, while there was also a few players who lured the minis, what the boss spawned at various % of his HP.