For the retail version, do you have the
patch installed? Any recently downloaded digital version should already be updated.
This problem should be prevented in an updated game, but if it happens in an unpatched game, installing the patch will not fix it if the issue has already occurred.
Lowering the difficulty level may help, if you are not already playing on casual (it will reduce the damage done, hopefully enough it is no longer a one hit kill). If you left anything undone before entering the Hall of Echoes, a higher level and better equipment may help you survive their initial attack (without spending time in Keara's headquarters spawning opponents it would be hard to get higher than level 37, though).
You can return to the battle tower from the dragon sections of the Hall of Echoes, if you want to upgrade enchantments or make potions, etc (the teleporter will be disabled, so you can not go anywhere but the battle tower platforms or back to the Hall of Echoes).
Do you have your creature active? It (and a summon, if you know any summon spells, or have any jewellery with such a bonus), may get attacked first (might need to reload a couple times), giving you time to react. Drinking an armour and/or healing potion before they show up may help.
If you can pause the game when the conversation ends, you might be able to use Hide in Shadows, or something. If you can stay mostly behind your creature, it may block a spell cast at you, though that may be difficult if both Laiken and Razakel have over-powered attacks.
One person who ran into this bug used CheatEngine to fix their health until they got past the problem boss (though someone mentioned that Steam may have an issue with the use of CheatEngine, even in a single player game).
Where's the trick to Ba'al?[Not Sure if Bug][Spoilers]Killed InstantlyIf you can not get past this point otherwise, email your save to support@larian.com, with a description of the problem, and they should be able to fix it for you.
In XP the saves are in the folder
C:\Documents and Settings\ %username% \Local Settings\Application Data\Divinity 2\Savegames
or in Vista / Win 7
C:\Users\ %username% \AppData\Local\Divinity 2\Savegames
You may need to set Windows Explorer to show hidden files and folders (
XP, Vista,
Win 7).