It's definitely savage level. I dunno about like 4th floor savage but it's definitely above EX and more in line with 2nd floor. The difficulty is also higher because this seems to have many more "prog liars" due to the increase of players in each lockout. There's no barrier to entry at all so people without EX or savage experience can join.
If this were an 8-man fight it'd be EX level. But it has 24 people and getting all of them to coordinate makes it harder than EX for sure.