There are both Damage Walls and Mines in the dungeon. You want monsters that can deal with both hazards. Have at least 2 monsters that do and the rest to deal with just one of them. There will be a Clone Tsukuyomi alone with the main version. Dealing damage to the Clone version will also deal damage to the Main version. The Main Tsukuyomi will have her DEF increased so focus your firepower onto the Clone version