Evards still causes damage, the save is only vs the paralysis effect, which freedom (and even clarity) will keep you immune to (as the paralysis effect is a type of mind applied effect.)
Evards is a fun spell, up to half of the tentacles can hit you at any given time, and running through them to trigger more tentacles to hit you is pretty brutal.
If you want immunity to the damage, invest in bludgeoning resistance paired with a ghostly visage potion, or outright drink ethereal visage.